First, let me say that it's awesome that you're open to other opinions and willing to listen and possibly change yours. I hope I am too.

For your argument on the pool of competition: that is very hard to estimate. Sure, we can just glance over the stats and say that Curry raining 3s, Harden dropping 40 points left and right, Westbrook averaging triple doubles, etc. makes today's basketball way more competitive. However, Dirk shouldn't lose any credit for the competition he had at the time. For one, his competition was still legendary, with many Hall of Famers in or near their primes. Second, he had no choice but to play in that era, and he won an MVP in it. Who's to say that if Dirk were born 10 years later he wouldn't win an MVP today? The game evolved a lot since, and he may have ended up having worse career, or a better one, no way to tell, really.