Cabs, MSTR vs BOBJ? There's a familiar situation...now, I don't know BOBJ that well, but I do have a couple of things to say about MSTR...
I think it's fair to see MSTR as more high-end, power-user type development environment in it's out-of-the-box form, but that doesn't necessarily mean that you can't build the simplest, most user-friendly reporting system with it. IMO MSTR have gone to great lengths to simplify the reporting environment to the extent that you can pretty much choose the level of complexity you deem fit for your users. Broadly speaking, Desktop is for the power-user; Web is for the user who you want to guide through the reporting environment; and Narrowcaster is for the user who you just want to send information to. Or to put it another way, Desktop is for 10 users, Web is for 1000 users, and Narrowcast is for 100000 users. And you can customise each to the nth degree as you see fit.
As far as the users needing to understand databases, and schemas, and SQL, the whole point of the environment is that you can hide all that complexity away and present the reporting environment in the way the user understands - as his business works. And his business might well be highly complex behind the scenes, but so what? You have an engine and an environment that can support it.
I would suggest you take a look at the OLAP Report for more information.
And just to end, if we all bought software based on market share, then you should perhaps be looking at Microsoft and Cognos.