I agree that the Latford system and other similar flat points scales are quite flawed and do not distribute points in a sensible way that rewards top performance. I commented on this during the pre-Chase days, though I didn't post much on racing forums at the time. As you say, winning and finishing toward the front is under-rewarded, and safe mid-pack consistency is over-rewarded. I think abomination is a bit strong. There are occasions in which the wrong driver won the championship, but I can't think of any in which the champion driver wasn't clearly among the top two or three performers for the season. If comparing to the current system, it is still quite possible for a driver who isn't among the top five over the course of the entire season to get hot in the playoffs and win the Homestead finale. Less so now than from 2014-2016, but still feasible.
That possibility certainly exists in some of the major team sports as well (sixth-seeded wild cards have won Super Bowls). My opinion is that playoffs and 'postseasons' are much more inevitable and natural in team sports than they are in either individual sports or motorsports, as evidenced by them evolving much earlier and more uniformly in the former than the latter. I agree that playoffs are largely a commercial concern, and it is why they continue to expand in several major sports. NASCAR's attempt to graft a playoffs onto its season would be easier to defend on these grounds if it had been commercially successful. It has not. There is no actual evidence that interest in the latter portion of the season has been improved. Only two major variables seem to govern the differences in viewership among NASCAR races: 1) when it occurs on the schedule (earlier races tend to rate higher) and 2) which track it takes place at (some notable venues are significantly more popular). The only event that has shown an increase relative to the season at large is the Homestead finale. That's it. Playoffs cut-off races don't rate higher than others, showing that NASCAR's version of eliminations don't move more fans to watch. They hype those endlessly, and the general audience doesn't care. They could achieve the same result with a 35-race regular season and one-off finale.
Is there another example of a sport that has created a playoffs, and after a long period the playoffs portion of the season is much less popular and viewed than the regular season? If so, it is probably the best argument possible that that sport doesn't benefit from having playoffs, or at least that it shouldn't be a major focus.