You made me smile Roger. As you know, we've trodden a similar path through two industries, but the world has changed. The simple answer to your question is "cost." Issues now get a Pareto test applied, and the big stuff gets worked-on, and the smaller stuff has to wait. Incidentally, JLP seems to be an IBM house (he said with some smugness), so you can't say they don't have access to rigourous methodologies. The trouble is, if you apply the attention to detail you perhaps should, you're late to market with features consumers (apparently) want.
Nowhere do you see this more starkly than in the Internet of Things (IoT) and mobile devices. The half-finished nature of the firmware/software in most products is staggering -- if they left the GUI in a mess, what's broken out of sight? Well, battery integration, evidently! And the security of the devices, so we're told. Get an IP camera and broadcast to the world -- not pictures, but share all your private network data with people trying to steal from you.
Meanwhile, back at Wacom. I have a few questions of the OP:
Firstly which Intuos are you referring to?
Stupidly (and marketing decisions are often VERY stupid), they've mucked about with the branding, so Intuos no longer has a clear meaning. There's quite a difference in behaviour between the two lines (I & Ipro), and the drivers can't identical (well, they could roll it all up into one, but the driver would be huge).
Secondly, what's the nature of the problem(s) and are you seeing them, or thinking of buying one and wondering about?
Wacom's business relationship with Apple is almost certainly at a low point, since Apple is obviously going after its market now. I wouldn't be surprised if Apple has cold-shouldered Wacom, as the margin on it's stylus ("Pencil") is huge, and it has no commercial incentive to do the integration properly.
For quite a few years I worked alongside people doing OEM hardware integrations (from the peripheral point of view). It's a two-way street. You can make your product as compatible as possible, and then the OS owner will go and do something unexpected, which breaks functionality. It's almost impossible to make complex hardware work correctly (and Wacom Pro tablets ARE complex) without cooperation. Our products had DIP switches to turn on/off various non-standard kludges, and we had a well-documented and agreed standard interface (SCSI-2 and SCSI-3). It's much harder in an uncontrolled consumer market.
In short tell us more aboutthe issues...
E.