In what way would this work against abusive votekicking? If people want to kick you on purpose, they'll still kick you. If they need to type a line they'll just type something senseless, or lie that you are rude / abusive.
Also when you want to change a map, you can only have one real justification, that is that you prefer that one above the current one. It's a bit pointless to say that you like the gameplay better because this is obvious from the fact that you want to vote for that map. Same goes for votekicks, because when you kick someone you're mainly saying that you don't want him in the server. Although it could be useful for people to know why you don't want someone in the server, they'll never know if what you're saying is true, and can't really use this extra info as something to balance their vote on.
People usually take very little time to vote for a decision, they just choose what benefits themselves most. If they're winning the current game, they'll vote negative, if they're far behind they'll vote positive for a new map. When someone annoys them because he or she is too good, they'll be easier seduced to vote in favor of a kick. People simply can't possibly know if your request to votekick someone is genuine due to his rudeness which you state or simply because you don't like him personally.
Although this idea wouldn't hurt the game and probably prevent some rare voting problems, the only real solution to this is to join servers which don't allow votekicks or respectable server with core members who respect anyone who respects them.