Yeah, he isn't a league average first basemen. 1 negative play/error every 5 games comes out to about -13 runs over the course of the year. Those 21 plays last year results is -6.3 runs. His RC last year was top 5 at 135. He's 129 Net. That is not average. If every negative play resulted in a run and every positive play resulted in taking away a run, then you could make the argument. But it doesn't.
For the guy who started the thread, you are not going to see an excess of negative plays if his range is above the recs. And his 20 glove should not result in so many errors that it would prevent you from putting him at 1B. I was able to maintain the best pitching in the league last year, with a tie for the 8th best fielding percentage with a guy who would be far worse than an average range/below average glove player.
Is a guy like Snow ideal defensively at 1B? Of course not. He would be best served as a DH. As a DH, he doesn't lose any value. But even after the update, you can still put a elite bat/defensive liability at 1B.