I think it's so common now because Apple has become so popular and trendsetting. Apple have always been very opinionated but they've steered the industry along with them. Everyone follows them in some way, like when vista basically copied Aqua and when they moved to flat design everyone followed.
Opinionated software works for simple apps but not for whole OSes IMO. I'm glad there's still systems around that offer more choices but they are becoming more fringey now.
The same if you want an OS without any kind of telemetry. Neither Microsoft nor Apple are saints there.