I actually agree on the spirit of your points. I still think MoS is not a good movie (though not terrible) and I think BvS is trash, but I feel like BvS had a lot of great ideas (and some bad ones) and the actors really brought their A game. Its problem was that it was bloated, overstuffed. Its right there in the title: Batman v. Superman: Dawn of Justice. Its trying to be a Batman reboot, a Man of Steel sequel, and a Justice League set up film. Had it chosen one of those, it could have been great. But it tried doing all three and ended up giving none of them their due.
The whole film reeks of executive meddling. Like someone called up Snyder et al and said "Yeah, Man of Steel didn't do very well. Batman sells. Put Batman in the next one." And it changed from Man of Steel 2 to Batman v. Superman. Then, a little down the line, they called again and said, "Yeah, Marvel's running away with the shared universe thing, so BvS also needs to set up a Justice League film." Look carefully, and you can practically see the stitches where the Joker was cut out of this thing. Now, Suicide Squad looks more and more like "We can be Deadpool/Guardians of the Galaxy too! Look how wacky Harley is! Do you hear that pop music?"
The problem, however, isn't in the reviewers or the fans who criticized MoS, nor is it really Snyder's fault. The problem is DC/Warner Bros. They don't trust their directors to make good films, they don't trust the franchises they're making them from, and they don't trust fans to go watch the films unless Batman's in them and they can say "Look, we can be like Marvel too!"
If you told someone ten years ago that Marvel would find success with Thor, Ant Man, and the bloody Guardians of the Galaxy, they would have said you were crazy. But Marvel trusted their directors to bring out the spirit of the source material, trusted that source material to be strong enough that people would like it, and trusted their fans would go to theaters to watch the films. They didn't try to have "Hulk v. Iron Man: Birth of Vengeance" or something like that to introduce people to the MCU and the Avengers.
DC needs to stop trying to play catch up to Marvel and start doing their own thing. If they keep chasing Marvel's tail, they are going to keep falling on their face. DC did their own thing with Flash and Arrow and (while I won't say either series is perfect), they've had success there. A good (or even decent) second film could have helped this franchise. Heck, look at X-Men, which didn't have a decent installment until First Class and is now going very strong. But DC panicked when Man of Steel had middling reviews (not even awful; middling) and ended up sabotaging their own franchise.