Other than a handful of fans on the internet, next to nobody is calling for Mullin to go. I doubt there are many, if any at all, influential folks around the program calling for a coaching change.
Realistic expectations heading into this season were 17-19 wins and competing for a bid. That was with a healthy team and, as many have pointed out, the risk of significant injury came back to bite. The staff knowingly took on that risk because building a balanced, stable program takes more than 2 recruiting classes. If we convinced Darien Williams and Malik Ellison to stay, or added a low-major grad transfer big man, perhaps we'd have 2 more wins at this point.
I, too, am underwhelmed by Mullin's coaching this season. But he is not on the hot seat. Even if there was a legitimate basis to get rid of him, the university made a substantial financial commitment that is pretty hard to unwind at this stage. Moreover, does anyone think next year's roster lacks depth and balance? Keeping Ponds is key, obviously. Next season, the leap to national relevance must be taken.
By the way, St John's would be a top 3 A10 team right now (KenPom), and Jared Terrell is not better than Ponds or Simon despite being nearly 23 years old.