Well said, and I think there may be a lot to your thoughts. It would also explain why so many folks like me look at the designs and give it a "meh" when looking at them. While their build quality is still great, even cheap knives have bearings, flip easily, and are perfectly centered for under $50. And in this day and age of computer design and CNC part milling, it is too easy for all manner of designers and manufacturers to incorporate any and all aspects of knife making they want on any new models.
I think it was a sad day to see one of the original "overbuilt" tank of a knife go away, the 350. Personally, I always associated ZT with that kind of knife. I think taking it out of the lineup would be like Buck getting rid of the 110. There have been a lot of ZT models over the years, but that one to me was the best entry level ZT out there that was a really solid user. No need for improvement.
I am sure though, if ZT was selling enough of them they would still be in production. Obviously, they are in business to make money, so pruning the dead wood off makes sense. But I think they could spend some time making the knives they were known for, just hard workers.
Robert