Very true especially when implementing a forum into your site.This stunted ExpressionEngine's growth for the
longest time cause people had to bring their own forum(they have a forum module now,50 bucks)and when they
brung their own forum you had to register once to comment on the blog,then register again to participate in
their forum.
I think the free core version is to attract more programmers.While it has a large following,it has a small group
of developers.Nothing beats a community of loyal followers.Simple machines has a lot of contributers,they mentioned something about releasing a CMS about a year ago,is that what this site is built on or is it home brewed?