I completely agree, but it was very interesting to watch a top professional of Starcraft2, "HeroMarine", take over as the top player of the newest Age of Empires.
But it is very similar with RTS, there is a huge crossover (although one factor here is that AoE4 isn't popular with a lot of the AoE2 crowd, another factor is that AoE4 has been a bit of a flop...pro games are getting terrible views so many are just choosing to stay on AoE2).
But there's definitely a lot of parallels between the games.
I'm bummed we don't have more of them.