Let’s analyze these two sides.

Supporters of Ashwin

1. Would they have said the same thing if the batsman in question would have been a Kohli or a Dhoni?
2. Spirit often overrides rules. If you see a very old man jumping a queue, you do not say, “Hey, fall in line!”. You say, “Never mind, he looks very tired and incapable of standing in the queue longer!”
3. If the Indian test team repeatedly fails to score 200 in the fourth innings of a test and does not learn from old mistakes, what makes us think Butler would learn from his mistake?

Opponents of Ashwin

Mostly, they are practising hypocracy, since some of them themselves have violated the spirit of the game by claiming a catch that bounced before them, by running out a batsman who went to congratulate the centurion at the other end and was returning peacefully to his crease(England did that to Muralitharan); by tampering with the ball etc.

Those are more serious crimes in nature and they should have thought before making their respective mistakes. 

BUT there could be some decent fellows who never made such mistakes (Or never played the game at any serious level) and are saying that spirit of the game was violated. And they have a right to feel so.

What ICC must do to prevent this?

1. The umpires should ask the bowling side if they would like to reconsider their decision. Sometimes one regrets what one does in the heat of a moment.

I remember that Ashwin (while representing India) Mankaded Lahiru Thirimanne of Sri Lanka in a group match in the Commonwealth Bank Series 2012 held in Australia. However the standing umpires, Paul Reiffel and Billy Bowden, after discussion asked India if they wanted to reconsider that appeal and Indian captain Virender Sehwag withdrew the appeal. Sehwag told them that Ashwin had warned Thirimanne before running him out, but since they are appealing to his nobler side to reconsider his appeal, he would like to withdraw the original appeal to stay within the spirit of the game!

(Team India was led by Virender Sehwag since MS Dhoni was banned for one match for slow over-rate. Sachin Tendulkar was seen advising Sehwag to withdraw the appeal!)

Thirimanne was mankaded before ball # 39.3

Did he change his behaviour after the appeal was withdrawn? Only for a ball(39.3). He was seen going out of his crease even before the ball was released again in the same over as well as the next over. So the batsmen who take advantage of this, continue to do so.

http://www.espncricinfo.com/series/8531/commentary/518963/india-vs-sri-lanka-8th-match-commonwealth-bank-series-2011-12?innings=1

For the record, India lost that match!

Pakistan batsmen benefitted twice due to the spirit of the opposing teams in my memory. 1987 World Cup, Courtney Walsh did not run out Saleem Jaffar, and WI went on to lose.

Mohammad Rafique of Bangladesh did not run out Umar Gul of Pakistan in a test match which Pakistan went on to win by one wicket!

So we have more examples of teams being nice and losing due to that! (Or at least they are highlighted more often!) 

What is surprising is how acting according to rules is against ethics. Now that all players are aware of that rule, should the bowlers get at least this relief that they do not have to warn?

ICC ought to bring in following changes to the rules.

1. A bowler/anyone from the bowling side should warn a batsman via the umpires that he is backing up too much.
2. If the batsman still continues to do so, the bowlers have a right to try running him out without feeling guilty.

With this rule, the guilt and spirit is taken care of and we run the game as we run the other parts of the game.

At times, the batsmen realize that an extra fielder is inside the 30 yard circle and they do not warn but wait for the umpires to signal a no-ball. The same way, it should be left for the fielding side. If this is not acceptable, at least the rule should be changed as above!