That never really bothers me.
I think it takes a lot of awareness to know when to suicide on the point and when to stay alive. It's the most chaotic point of the game, so it's very easy to not know if a teammate is going to take care of it for you, or the clock/overtime meter is running out. And it's probably pretty rare for a suicide to end in a win like that anyway, since your tanks are probably dead if they aren't on the point, and you're not likely to turn the tide as you die on the point.
It seems like a type of recency effect to me, where people inflate the importance of the very first and very last moment, and completely forget about the middle.
https://en.wikipedia.org/wiki/Serial_position_effect
You see this all the time in professional sports interviews, where the interviewer wants to ask about something that happened at the start or end of a game, and the athlete well versed in the flow of the entire game redirects to something in the middle as the most important moment.
I find it a pretty important for self improvement in any videogame to actively work against falling into that fallacy in self reflecting on why I won or lost a game.