This is a good point - and the only possible reason for treating it as less serious than Rose, besides the one-off nature, might be that it happened before gambling and game-fixing was established as a cardinal sin in 1920. Rose had no cultural excuse; within a liveball-era baseball context what he did was quite literally worse than killing someone.
Well, a lot of people did bad things. I have stated why I believe that’s no defense for Rose, who did the worst thing you can possibly do in baseball, but the Hall refusing to acknowledge any distinctions and deferring to the MLB restricted list wasn’t a great move. Right now we have a situation where every sportswriter makes up his own mind about whether candidates whose on-field merits make them automatic HOFers like Bonds and Clemens should or should not be kept out for steroid use. The central problem that any deep analysis of the Hall of Fame keeps running into is that it has no meaningful criteria instructing the writers on how to make selections.
The gambling scandal overshadowed some other legitimate criticism of Rose i.e. that he was totally washed up as a player by 1982 but hung on embarrassingly long to get the hits record by abusing his position as player-manager and his status in the Reds organization. Part of the sense of betrayal people felt was that he had cashed in on a lot of goodwill to make that happen and it turned out he was behaving like a complete asshole the whole time.
He lost his power by age 30, he was never a real threat on the basepaths despite the “Charlie Hustle” reputation, and the reason he could boast of playing significant time at five different positions is that he was a defensive liability at all of them and was constantly being moved around to make room for better fielders. Yet, I actually had some crazy person argue with me last year that he contributed more to the Phillies in his age 38 through 42 seasons than Bryce Harper (who signed at age 26) will - that’s how effective Rose’s reality distortion field is. On performance alone and ignoring the scandal, he’s still most likely a deserving Hall of Famer based solely on his ability to grind out singles and walks over such a long period of time, but there is much to criticize about Rose the player. There is also something to be said for the fact that his HOF case is extremely dependent on his image as a “hustling, play the game the old school way” guy and transcends his shortcomings to some extent - just like Nolan Ryan being a larger than life figure means he needed to go in the HOF even if his control problems and their effect on his advanced metrics were pointed out - but that works both ways. If your HOF candidacy is based on Pete Rose the holistic, larger than the sum of his statistical parts guy then Rose’s character flaws are part of that calculus just as much as Ryan’s famously clean and hardworking lifestyle were for him…