I agree with OP. At the beginning of the game you can tell if they have gone air and later you can normally know when they have got Dreadnoughts from the numbers. But sometimes the numbers do seem out of wack with reality and much of how it is made up it still opaque. It is bugged too with sometimes giving a tiny number when it shouldn't.
For skirmish games vs AI there should be an option to keep it as lots of more casual players just play that mode and I imagine they like seeing those numbers.
As mentioned AA creep can be a problem for scouting. They are also incredibly tough early game and I even think they can imbalance the game a bit as if you have to kill several of them and your opponent doesn't they can spread faster.