If you don't find the complaints annoying, then there is no problem, we can maybe disagree about the observation, but that's another debate.
Now, if you do find them annoying, it's very likely the complaints are made by fans/haters of Y and thus you find them annoying, from that would follow that in all cases where the complains are actually made by the fans/haters of Y, your statement would logically contradict itself.
No one has a crystal ball and even if one would have it, its prognosis would not be a legitimate argument in the debate, as any debate about the future would be made pointless by it.
If on the other hand we believe that we all have crystal balls, but they are showing different things, they are made pointless in themselves, let alone in terms of debate.
I'm not disputing Belgians knowing their talents, but talents are just potential until actualized.
Is Remco a great talent? Sure.
Did he prove his great talent in TT? Of course.
Did he prove he can dominate any TT anytime? Not yet.
Did he prove his great talent in some classics? Most definitely.
Did he prove he can compete in all of them and is the best current classics rider? Not yet.
Did he prove he can continually dominate 1 week stage races? Not yet.
Did he prove he can compete for the win in second level GT? Yes.
Did he prove he can win a GT against top level competition? Not yet, maybe Giro can give us some (not all) data on this.
Sure one can always make "blind" predictions and feel good (or brag about it) when the predictions turn out to be correct. But one also has to acknowledge when the predictions turn out to be false (and take the bragging of others).
Needless to say, bragging before results are known is childish and in terms of debate only serves to provoke the opponent on a non rational basis. (There were certainly examples of that from some members of this forum.)