I believe much of what Adobe actually implements in AI all comes down to cost.
Surely there are users, or even developers, that see the pain points and make them known. But ultimately I think what is or is not developed, refined, and/or implemented is all reduced to cost vs sales equation somewhere. The accounting department dictates just how much dev time can be assigned. Then it's up to team leaders to sort out what can and can't be done for that cost.
Adobe adds stupid stuff at times all in a quest for more $$$.
- Example, the Bounding Box. It was aded specifically to make CorelDraw users more comfortable in Illustrator. And it has absolutely no unique feature within Illustrator. It's an application feature that is nothing more than overhead.
Sometimes it seems overhead to the application is added to combat anyone actually having to learn a feature set as opposed to merely throwing everything directly in front of a user.
- Example, the Free Transform Tool and it's pop up tool bar. None of those "tools" are "new". All those transformations have been possible with the Free Transform tool since the 1980s. But many users, not having actually explored the Free Transform Tool features, were unaware that those transformations could be performed. So, Adobe added overhead in the form of a pop up tool bar needlessly to placate the ignorant sector. And then they sell it as a "new feature".
And then there are times where I believe the dev teams know they need to improve things, but due to cost limitations they are not allowed to. New bells and whistles tend to garner more new customers (subscribers) far, far, more than improvements to existing, sometimes little used, features.
- Example, Live Color. Such a powerful feature but has so many limitations in how it's implemented that you can easily hit a "wall" and have to step back, start over, and rethink a direction. I believe Devs know all this. They simply aren't allowed to devote time to correct it.
All of this, I feel, leads to an application that quickly become "bloatware" and actually less usable.
I, personally, have never liked any "CC" version of Illustrator. They all see far to "muddled" while working. I can't specifically state any direct mechanics that are problematic for me. It's all more of a "feel" to the application.
I much prefer CS6 to this day. Even though CC does have some feature sets that I can see as useful to production. CS6 "feels" snappy, responsive, and "awake" - for lack of a better term. CC versions "feel" like they are in a daze, everything feels like it's more concerned with being "smooth" in it's mouse movements than it is in being accurate. I feel as though I'm working in 2 feet of water when I use any CC version. None the less I do use CC at times for a couple features unavailable in CS6. However, since CS6 I have not been in a hurry or felt compelled to move my work to CC. There's little need 99.9% of the time for me.
And, admittedly, the entire "subscription" model where I'm locked out of any of my copyrighted work if it's saved in a CC format unless I pay Adobe really irks me. I can't have my artwork being help hostage as a "business model".
Unfortunately, due to the age of CS6 and how fast turnaround is in the industry, many users only know CC versions and that's all they'll ever know. And you simply can't know how much better something can be if you've only ever been exposed to one flavor. It is never surprising to me if younger designers merely assume "that's how things are". They've been told to accept what they are given... and they don't know how much better something could be.