Figured I'd take a moment to explain some of the thinking here.
The DBC14 style of career skill progression that a lot of people liked had a major flaw in that the only way you could get good at something was to do it repeatedly in match, which would likely have meant getting out more or bowling worse, which would impact your selection. Adding the Gym among other things lets you then create a more fully rounded way of handling how a career player develops, you can just play the matches and ignore it all, but you can also use it to offset and work on your weaknesses in case you get stuck and can't get up to the next level.
As much as gameplay is the nuts and bolts of how the AI play, gameplay is also about what the experience is for the person playing. Feeling like you are stuck at a particular point of your career and facing massive grinding in club matches for years on end is just as bad of a gameplay experience as some other issues people raise.
The other aspect is marketing, while it's very much outside things I deal with, I'd suggest it's very hard to start a sales pitch with "this thing was busted". So we're not going to make a trailer showing off fielders throwing with their dominant arm, we're just going to fix that issue, and see if people notice it when they get their hands on the game. On the other hand, if there's a new thing you can go do, like a mechanic in game, or new cutscenes, it's very easy to convey that stuff to someone in a video. A lot of the improvements to gameplay are things you'll just have to play, or have other people you trust play and review it, so it's something that's harder to have at the forefront of promotional stuff.