Because EoSD's gameplay sucks compared to every other Windows Touhou game.
I don't think it sucks that much, especially with hitbox patch (which solved my main gripe about it).
Sure there is no cherry/human-youkai/faith/communication/ufo, or anything like that,
but I don't think that makes it not fun.
Plus, once you get used to staying the hell away from metal fatigue bullets,
and recognizing that the red part of bubbles kill you, it's not that bad.
I find EoSD a hell of a lot funner than UFO.
Same here. I can fight Sakuya and Remilia in lunatic pretty well (even going through walls!),
but when it comes to Shou and Byakuren... :V
Oh, and personally I hate having to collect ufos. I always end up collecting close to 0 resources even in hard.