Well I think ME revolutionized the way most people play the game, not sure if more people go for single missions or campaigns but that's about the tastes anyway, as for other things, mainly "obscure Euro-jets":
Well the EXP2 brought new Hunters, Lightnings and F-100A/C jets I would rather call that a British-American connection, OK the Hunters had such a large service all over the world you could call that an "Euro-jet" but most certainly not obscure as we are talking about a true legend here, it's like saying Spitfire is "some obscure Euro-plane" but I'm missing my point here...
On the other hand EXP1 had Meteor, Mystere and P-51, that is IMO more into "obscure Euro-jetting" than exp2.
Now when you really look closely at those two titles you can see something interesting, it's recycling, because exp1 brought 3 brand new never before seen planes in SF2 series while strictly looking exp2 only had the Lightning because new Hunters and SuperSabers are just new variants of existing planes, yes the pits are new and awsome and everything is really cool - to us, the very few that really appreciate multiple variants but casual gamer just sees another plane of the same name and same basic look, he does not care that much about variants like we do and that is I think also one of the reasons exp1 sold better than exp2
Nevertheless I think you nailed the head with the intro remark, we are indeed in turbulent economy time...