Not tapping out doesn't show heart. It shows ignorance and pride. Any experienced BJJ player or MMA fighter knows when they are going to pass out and are unable to escape the choke, at least most of the time. Holmes was not attempting to escape in any meaningful way, she was just being tough and prideful and hoping the choke wasn't on well enough to pass her out (which is dumb because of who her opponent was and because it was on really well). At least as long as UFC is a sport and not a cage brawl, not tapping out in a situation like that gives Holmes no advantage and only endangers her health. Those last arm movements were spasms from lack of oxygen to her brain. As someone who has fought people with that irresponsible attitude, it is disrespectful to your opponent to put yourself in that situation because it can result in serious and long term damage that could seem like your opponent's fault (when it is really your fault).