Well I don't think it is wrong. If the blinds are, let's say, 100/200 and that guy goes for a 500 raise, unless someone raises him for at least 300 he is not able to re-raise. So, even that guy had 790 instead of 510 and goes all in, in this case our original raiser won't be able to re-raise. And I think that's fair enough, even if it bring some callers, it is a part of the game!