See, the vassals and inheritance and whatnot is what makes it interesting to those who really dig it. Its a bit like playing A Game of Thrones the game, but its also got a bit of dwarf fortress to it, you know, a lot of shit goes wrong, you feel like you're always working uphill just a little bit, especially when you get a stupid or incompetent heir, etc.
I can see why someone would prefer EU over CK for the reasons you've mentioned. It just seems strange to me, as someone who likes CK2 probably a bit more than EU3, because CK2 is EU3, but with that added layer of complexity.
I dunno. To each his own and its totally cool if you prefer one over the other. I like to look at CK2 as a story telling game, very Dwarf Fortress in that respect, you know, shit HAPPENS and you respond to it, oftentimes unsuccessfully, that is fun to me because it provides a sort of narrative focus to the gameplay that is somewhat stripped out in other Paradox grand strategy titles I guess.