EDIT: Since I keep getting the same replies, I'm gonna edit it here too:
1. When you are in maintenance mode and you still manage to introduce more bugs than you are fixing then your are doing something wrong (usually that's a result of limiting the budget of a department and as a consequence hiring less experienced developers)
2. Every new feature the last few years has been ported from iOS and without much care. I still can't believe they have yet to make Siri and Spotlight one unified product (at least make Spotlight more powerful, I can't even set a timer with it).
And to add to this, being in maintenance mode doesn't have immediate effects. If Apple continues like this somewhere down the line macOS is gonna end up quite behind (and a big mess due to points 1. and 2.)