This is pure conjecture, but I suspect that a lot of the changes, especially things like shove as a bonus action, are things that rarely and situationally a human DM would let you get away with if you made a strong case for why it could be reasonable in that particular scenario.
Since we don't have the benefit of a human DM, the design choice boils down to "should players have options that a human DM might occasionally allow?" And since the only two possible answers to that question ate "no, never," or "yes, it's allowed," to my thinking that's a no-brainer. People who need shove to be a full action are perfectly welcome to forgo their action on a turn when they shove.
And let's be real, shoving has been *way* toned down from what it was a couple years ago, so there's way less cause to use it. Also, you do have to be careful and selective yourself - "after I shove this dude, do I have enough movement to get clear of this spot that's obviously a good place to shove from?"
People who want to cheese shove as a bonus action will learn to be much more selective in their use of it.
I guess the point in trying to get at is that I'm fully on board with OP in this, and many of these rule changes are good because they can make your game feel more like table top.
(I'm not feeling as generous when it comes to race ability scores, but oh well, I refuse to let that stop me from fully enjoying the game)
