These figures shouldn't be surprising, though. WoT is successful in large part because it has no competition. WoWp has that in WT and frankly the game didn't do much of anything to differentiate itself from that product. It's clear WG is no Blizzard (or rather Blizzard back in the day) that can release a game in a competitive genre, make it better than everyone else, and draw in the crowds because of that.
Then again, if you take worldwide concurrency of WoWP and compare it to WT, the difference is not that big as WT fans seems to try to claim (ca 2x more is not that big difference for a game that's supposed to be "the bee's knees" - and quite a few people who were very publicly leaving WoWP some months ago are now getting back and actually are even being quite open about the reasons)... On EU the concurrency is slowly improving, though we are trying obviously to make it much faster (right now, by a crossover contest).
I think it shows (rather than "being there frst" - after all there were online games sometimes with better graphics trying to burst out around the release of WoT and they did not make it... There was competition), planes are less sited for casual gameplay (there is only so far you can go for arcade controls, you cannot do away with the fact it is in 3D and high speeds and that requires simply more skill etc.). It is probably also one of reasons hardcore sims went out of "wide public" fashion some time ago already and went to niche - old popular sims were, by today's standards, extremely arcadey (Aces over Pacific, Red Baron, all the oldies goodies) - but that also meant they were often quite easy. Now... Well, maybe arcadey MMOs will bring people back in, but as demonstrated above it seems that they may be a bit too hard (even such simple like WoWP or WT arcade mode)
It also shows that game should not be opened to audience too early. Early Beta was really not that much appealing and lot of people have impressions from back then.