I tend to agree with you for the most part about Apple focusing on the average computer user bein able to just use an iPad. It makes sense for day to day use. Especially with the power that the iPads can offer.
I still think Apple however can't stop getting in their own way with iOS and just don't seem to understand that if they're going to sell and market the iPad as a computer replacement than it needs to be able to do the tasks a computer can do.
it's gotten so much better especially with the latest Pro adding USB-C (all iPads should move USB-C). Heck, an iPad now is basically nothing more than an Arm based mac when you pair in a keyboard (and hopefully soon mouse).
but the artificial limits (no external storage, limits on some devices you can use, limits of the tools for the filesystems). As said, until Apple takes the training wheels off iOS, it's going to continue to get blasted by many people that iPads can't replace computers because of these. The question is, does Apple wish to relinquish a little more control to hit potentially larger audiences, or do they hold on and keep the course.
I believe if Apple keeps the current course of iOS and keeps parity features off iPad's that people look for in their computers, than the iPad market is essentially mature and where we'll see it stay. If they can open it up to make it more computer like, they may be able to grow and steal some traditional laptop purchases away