Well, I do not disagree with you about the Miata, I have not driven one, but I have heard this same thing over and over from virtually everyone that has driven one. Also, slow cars are more fun to drive fast lol, so that probably also makes a difference on top of the fact that it is incredibly light to today's standards. However, I am not sure about the safety of the Miata lol.In all honesty, I think most modern-day BMWs fall into this trap as well. Most of BMWs "sports"/sport-y cars are simply deconstructed from their sports sedans (rather than built from the ground up.) That is why the weights have been so insane on the previous and current-gen M-series vehicles (the new M2 weighs almost as much as the M4.) There are very few companies making dedicated sports car platforms today.
This might be sacrilegious, but I find the ND Miata to be more enjoyable to drive than my previous-gen M2; I autocrossed/tracked both vehicles as well. I switched to the M2 mostly to still have something fun to drive that was also a bit more practical (the 2+2 setup is perfect for me really.) The M2 was fun to drive (moreso than my Model 3), but I find the ND to be more engaging when cruising through backroads/track/whatever; for commuting, the ND is a chore lol. I'm a bit biased though in that up until my M2, I had mostly driven/owned sub 2800lb vehicles.