I mean I super agree with you. It is a better system in a handful of ways, at least on paper. But it's easy to forget how massive the casual audience is. I forget all the time.
"When I go to learn a new character, am I supposed to spend an hour learning their moves?" Is an actual statement I just heard.
there are games harder than Mortal Kombat and have a bigger casual adience and much more complicated commands.
Do you think, pressing an extra button that is not block hard?
Imagine having to press two buttons at same time and release one after one frame?
Imagine a Shoryuken motion where your perfect execution has to be just frame otherwise your character is garbage.
Not really on anyone's toe here, just an example that there is way harder games out there, and the casual crowd for that game is also bigger.
A fighting game shouldn't be to make everything easier, specially when you present consequences of having the block button multitasking with offense and defense, if you think this way, casuals will always get in the way of balancing a game which they could benefict when they get better, not only yo make things easier for them, but casuals aren't the only type of players beneficting for that change, pros take bigger advantage of things that was made easier when it was there to regulate them in first place.
A fighting game should give you layers to improve on, every pro or competitive fighter was a casual at some point in time.