Alright, I think I'll toss my two cents in this discussion :
Am I the only one that feels that ZUN's works are growing more and more fanmade-ish as time progresses?
I'd say ZUN only put newly acquired experience that he didn't have around the time he made the older game into use : the newer games's
style differs quite a bit when compared to the older ones, and
that's about it. Obviously, the older games's instruments had their own charm with them, and since these mainly gave image of Touhou, it's understandable that slightly getting away from it might seem like not fitting into what is usually thought that makes Touhou games Touhou like. Remember that ZUN
is an experiment maniac love experimenting with his games, regardless of what we'll think ; and if I may say, this game's pointdevice gimmick is quite an evolution compared to the older works (heck, the way he expressed this made me think he'd quit the traditional format of the games)
And about the fanmade-ish-ness of the newer games : I have to disagree with this because of reasons that have already been stated by other people. I'll just say that in general, the fangames are the ones trying to copy the style of ZUN's work: did you like a certain fangame's music more than a main game's music ? Then that has nothing to do with quality, only personnal preferences, nothing else.
If you compare the newer games's patterns with some fangames's patterns like, say, Riverbed Soul Saver's stage 5 boss's two last spells (and pretty much all of the phantasm boss's spells), the pattern start in a way, then it spreads, then it breaks and you get all kinds of bullets with more color than necessary: it doesn't have structure (I like RSS btw, I don't mean to insult it but seriously, some patterns are absurd) ; but the newer games have structure : the boss throw two to three different waves, rince and repeat, the color and patterns are not modern art level of ridiculous and, for the ones that rely on gimmicks, the gimmicks are pretty easy to figure out right on the go *cough*screen flip*cough*. There are actually more straightforward spells who are pretty simple but nevertheless entertaining (Doremy's spiral spells seems fun to me)
And what of the character design ? Well, IMO, some fangames try to make the character design TOO elaborate to be remembered or textbook touhou OC (trust me, they are easily recognisable) : design are nice and all, but settings ARE even more : anyone can give a character they make a backstory of some sort, but settings are not the biggest part of a character. Heck, just look at Cirno. Alright, so how is, say, LoLK in this regard ? Well, we have two rabbits with very PLAIN clothing but actual relevances to the plot. The end. There is more to characters than just frills, hats and drama.
And the music ? Well, like I said, fanworks try to be like official works when it comes to
recreating Touhou's atmosphere, BUT then again, ZUN makes sure the music
fits the game's atmosphere : is techno-ish untouhou-like ? Well, if the guy thinks it fits the atmosphere better, then that's it. Fangames do this too, but they copy the older touhou games's style IMO.
Anyway, to sum this up, IMO the problem is pretty much "how the series used to be" VS "what the series has become", nothing else. It's not getting fanmade-ish, rather the fanmade stuff became better at copying the official things. Besides, I think it's contradictory that the games's quality'll go down at the same time where ZUN's ability as a creator go up.