Alex,
Why? Well, limited opening/seasonal playability/lack of playing access. Artificiality, sub-air, overly green, too perfect, tree moving, coloured divot mix, dye in ponds, permanent TV towers, sensitivity to criticism - to much grovelling from too many - 'patrons' ha,ha, they're 'fans/spectators' and god forbid anyone mention bikini wax! Money - buying up adjacent land for big money and then parking cars there for one week a year. Sorry to those folks who love ANGC/The Masters, but IMO where once there was a invitational golf tournament that for years and years I looked forward to viewing there's now an annual circus, and one that's getting bigger by the year.
Plus as Jud T said earlier, there's "The issue...with all the wanna-be courses, memberships and committees who try in vain to keep up with the Joneses (!) by lengthening and greening their courses till the cows come home.....Envy does indeed run green." This aspect has, IMO, had a huge impact on the game over the last three or so decades, and unfortunately it's been a negative impact.
All the best.