There's no question that the Paladins should have made the NIT over a couple of the teams that did. But also, it's the NIT. It only became a thing back in the day because the NCAA tournament was limited to one team per conference. In the current scheme of things the NIT isn't important.
And while obviously the SoCon should do everything it can to build it's reputation, there's also some unrealistic expectations going on here.
Take Belmont for instance. They've been good every year since 2005 and have made the NCAA tournament eight times during that span. The Paladins have been good since 2016 and of course have zero NCAA appearances going back decades. Does it really make sense that Furman would finish slightly above Belmont in Pomeroy once or twice and suddenly Furman has a stronger basketball reputation? Obviously not.
And so far as the A-10, while that conference finished only one spot ahead of the SoCon, the 2022 difference in Pomeroy rating between #11 and #12 is more than the difference between #12 and #19. The SoCon has improved dramatically in the past several years, by far the most of any conference, despite numerous limitations. But again, how reasonable is it to expect that the SoCon looks good in Pomeroy for a few years and suddenly the entire nation is full of respect for what was recently a low-major conference?
Factoring in the number of NCAA conferences over time, the #12 conference finish this year is probably the SoCon's highest since WWII at least. SoCon programs will have to invest more just to maintain that level, let alone trying to match the A-10 or MVC.
The Paladins just have to keep competing at the top of the SoCon, wherever its ranked, and sooner or later a meaningful post-season will happen.