I would respectfully suggest that you are dead wrong here.
Yes, it required more engagement, but it's bad misunderstanding to think that means wargamers are the audience. On the contrary I think boardgamers were. To a wargamer 4E isn't that different from other editions in terms of engagement, but to a boardgamer, it's a much big jump in engagement.
If you look at my group, the two most casual players absolutely adored 4E. Seriously. One of them still grouses that we aren't playing it. This was a guy who was never previously a serious, engaged, tactical player, he was very much casual and about style. But 4E unleashed the beast and he loved it. In fact the two people who liked it least were the ones most keen on wargames, so there's that as well.
But even just my casual players proves that what you're saying isn't right re wargamers.