With a firm drive back to the bowler, Pragyan Ojha, in Australia's second innings, Nathan Lyon consigned Shane Watson to an embarrassing fate. Lyon, the No. 11, had faced more deliveries in this series than Watson, the No. 4 and supposedly one of the team's senior batsmen. Both men had played three Tests on this tour. Lyon had shown admirable fight and in two of his innings had lasted more than an hour. Watson managed that only once. Plenty of Australia's batsmen were culpable on this trip, but none more so than Watson.

After the match, Watson spoke of his disappointment at his own poor results but he also defended the wider top-order performance by saying the conditions had been difficult. If they were that difficult, how did Peter Siddle score a half-century in each innings in Delhi? How did Mitchell Starc make 99 in Mohali? Why did men batting at No. 7 or below top score in four of the eight innings? How was it that Lyon (244 balls), Starc (254 in two Tests), Siddle (350) all survived more deliveries over the four Tests than Watson, who faced only 239?

In the second innings in Delhi, Watson showed that while the conditions might have been challenging, he wasn't respecting them. On a pitch offering up-and-down bounce, pulling is fraught with danger. Anything that could threaten the stumps needed to be met with a straight bat. But Watson went for a big pull, the kind of shot that brings him countless boundaries on flat pitches in one-day and Twenty20 cricket, and was bowled when the ball kept low. It was a terrible shot in the circumstances.

Watson was the acting captain in Delhi and that made sense for a one-off match, for he is vice-captain to Clarke and was the logical choice as leader. But the vice-captaincy should not guarantee selection and Watson must be sailing dangerously close to losing his place. In the past two years he has scored 627 runs at 24.11 in 14 Tests. That would be acceptable if he was a bowling allrounder, but his primary role in this side is as a top-six batsman. On that alone he should be judged.

When the Ashes comes around later this year, Watson is likely to be bowling again. If he is making runs and bowling he provides valuable balance to the side; if he is still failing with the bat that becomes irrelevant. Watson will probably be in the XI for the first Ashes Test and against England's fast men he could score runs - he averaged 48.00 there on the 2009 tour. But then, he averaged 16.50 in this series having averaged 40.09 on his previous two Indian tours.

That Watson performed so poorly having played six Tests in India before this series made him the most accountable of Australia's batting failures, but he was not alone. The batting throughout the tour was characterised by a lack of patience and an inability to handle the turning ball. There are two sides to batting, the technical and the mental, and on both Australia were beaten soundly in this series.

India's batsmen set the example from the first Test. Collectively they scored six centuries and five of their batsman averaged 50-plus. They were patient and respectful of the conditions, they played with straight bats and they waited for the bad balls to put away. Too often the Australians tried to force the issue, hoping an aggressive approach would put India's bowlers on the back foot. Cross-bat shots and inadequate footwork proved extremely costly.

Three members of the top six averaged fewer than 20 for the series. It is no wonder Australia lost 4-0 with such a malfunctioning batting order.

Michael Clarke scored a century on the opening day of the first Test in Chennai but no Australian made one after that. Three members of the top six - Watson, Phillip Hughes and Matthew Wade - averaged fewer than 20 for the series. That is a figure that bears repeating. Three of the top six. Fewer than 20. No team can carry such inadequacies. It is no wonder Australia lost 4-0 with such a malfunctioning batting order.

As expected, Clarke was excellent in spinning conditions and Steven Smith's footwork also made him a valuable member of the middle order. Ed Cowan progressed throughout the trip and showed that he could bat time, generally forcing the bowlers to get him out rather than getting himself out. But overall it was a miserable tour for Australia's batsmen. The bowlers at times let things slip away but always they found themselves defending sub-par totals, often propped up by their own tail-end efforts with the bat.

It is becoming a worryingly consistent trend. In the past year, Australia have played 13 Tests. Clarke has scored four centuries and the now-retired Michael Hussey made three. Outside of those two, Australian batsmen have made only four hundreds in those 13 Tests: Wade has made two and Cowan and David Warner one each. It's more than two years since Watson has scored a century. In the past year, only Clarke and Hussey have averaged 40-plus, of those Australians who have played more than two Tests.

Often, Australia have got by on the backs of Clarke and Hussey, for before this disastrous tour the only series they had lost since the 2010-11 Ashes was against South Africa at home, and that could have gone either way. But now Hussey is gone and says he's not returning. Clarke cannot shoulder the batting burden alone. And a burden it has become.

There is merit in showing patience in a young, developing batting line-up. But can that come at the cost of a 4-0 whitewash in India and a couple of Ashes drubbings? The conditions in England will be more familiar for the Australian batsmen, but England's attack is full of quality. If the batting falters again in England, what then? Australia would face the prospect of retuning their line-up for another Ashes at home a few months later.

Australian cricket may not exactly be brimming with batting talent at the moment, as shown by the fact that Ricky Ponting, who retired after a woeful series against South Africa, easily topped the Sheffield Shield run tally this summer. But there are other batsmen worth trying. Usman Khawaja is one. Alex Doolan is another. So is Callum Ferguson. The in-form veteran Chris Rogers would be an ideal Ashes pick if he wasn't an opener. Australia have enough of them already.

But what this tour has highlighted is that substandard batting cannot be tolerated indefinitely, especially from senior men like Watson, otherwise this won't be the only thrashing Australia will receive this year.

Brydon Coverdale is an assistant editor at ESPNcricinfo. He tweets here