"it's a way to protect you from losing a game due to non-chess circumstances of short duration."
If it's just a game, it shouldn't be a big deal to just lose the game if you have to. It's understood that you accept the risk of something happening when you play an online game, e.g., your kid distracting you, having to go to the bathroom, whatever it may be.
On the plus side, you could say that it's an incentive to play more honestly, and that it would increase the amount of honest players. Though, that's pretty speculative, and it's probably a lot more costly to fairly create a system like this than the benefits it could give.
I know - me too. Just my last blitz was lost that way - and an extra 3-4 BONUS MINUTES would have saved a winning position against a guy rated about 2160 blitz...
I believe that it can't really be abused, actually - because if someone tries to use it for any purpose other than in an emergency - then whatever they gain through that use (IF they gain it) - will be lost at a time when they will have a REAL emergency with no BONUS MINUTES available.