My highest bullet rating is 1200. This is not because I was once a moderate bullet chess player. This is because 1200 is simply the starting rate of everybody. I think that it is more appropriate when the highest rating is the rating that you reached by winning games. So when you cannot play bullet chess you're rating will drop to for example 800 then you're highest rating is still 1200. After you won a game against a 700 your highest rating is 700. and not 1200.

who cares? some people just dont play that one type of game.

I think you misunderstood.This is not about people having a 1200 rating because they didn't play that kind of chess.

My proposal was aimt at people (like me) that play but have a rating lower than 1200. For those people the 1200 has no value at all and they maybe want the highest rating number adjusted to the highest rating they did reach.

I agree, it should be the highest rating achieved with RD < 80 or RD < 100 or some other reasonable value that indicates the rating is somewhat accurate.