She, like any sane person would do, asked for medical help when she was having trouble breathing. The trainer and the doctor allowed the MTO and they decided that the MTO would happen inside. It's not like she suddendly left court with no reasons and forced people to follow her. Everything that happened was allowed by the rules. Like it or not, she did not cross any rule.
As for the timing of the MTO, it's not the first or the last time a MTO is called at a crucial moment, and yet no MTO never was followed by such a backlash. The whole thing was emphasized by American media and American pseudo-journalists on twitter. A lot of people who found it easy to trash a 23 yo girl for something allowed by the rules while none of them talked about the dubious sportmanship of Federer who behaved like a total jerk the next day. Doubles standards much ? Oh yeah, Federer was not facing America's next Superstar.
You're right. Taking that time out due to nerves and choking was within the rules, but don't blame the American media for what ensued because that is 100% on Vika and her team. Of course, there was going to be backlash because most people do consider what she did "cheating within the rules". Nevertheless, it is allowed and at least she was being honest. So why did her story change by the time she got to the press conference?
After meeting with her team for over an hour, Vika told the press that she had a rib injury blah, blah, blah...which completely contradicted what she had said about choking in numerous live interviews. Taking the time out due to choking IS within the rules, so why didn't she continue to say that???? Because her team knew that, despite being allowed the TO, Vika had fucked up by admitting that she used it that reason.
Look, Vika won the title and clearly these facts are irrelevant to you. You're a Vika fan who chooses to blame others for her actions and believe what you want to believe. But honesty is the best policy. Had Vika not changed her story, the press/public wouldn't have been nearly as hard on her. However, the attempt to spin it REALLY pissed people off and made her look shady as hell.