Yeah, I didn't see anyone here saying Velma should have accepted him. (Or that Roy was a misunderstood swell guy, either.) I do agree with @AuntiePam that there was some nice nuance in the writing, that just as in life, nobody's 100% good or evil. A basically nice girl could have her thoughtless and shallow side (she could have expressed a commensurate degree of gratitude for the really huge gift he gave her; but she didn't owe any more than that), that a person with a disability isn't necessarily a saint, and that even a career criminal can have a yearning toward a different life, even as he kind of knows he isn't going to get it. In fact, the latter sort of combination, the softness within the hard guy, was kind of the Bogart specialty, wasn't it?
That "yearning toward a different life" was the undercurrent of the Velma subplot, which I didn't acknowledge above, or perhaps really understand until I saw Colorado Territory (which I've now done), where I think that thread was handled better, his hope not unraveling till the last minute (but truly shattered then, by her venal behavior). And having Dorothy Malone meant that there was more texture in her character.
The two make an interesting pair for comparison. Overall, I do find High Sierra the more classic statement of the story, but certain elements are handled better in Colorado Territory; and even when they aren't, it's refreshing to see a remake that was intelligently enough made (same director, Raoul Walsh) to rethink details appropriately for the new period and situation. Both movies can live side by side very well.
I'm not sure about Joel McCrea as a trade for Bogart. I'm on record as being a fan, considering him underappreciated for the sparkle he brought to Sullivan's Travels, The More the Merrier, and especially The Palm Beach Story. But he spent the majority of his long career in Westerns, and in the ones I've seen, I miss the leavening of humor that completes him for me. (Though he finished strong, in the magnificent Ride the High Country.) There's a repeat cast member from the first movie, but not as the same character. Henry Hull, the doctor who arranged the operation on Velma, shows up 8 years later looking younger and healthier as Julianne's father. The former role sported some of the most unconvincing old-man facial hair I've seen, so I was relieved to discover that it wasn't his own, just bad makeup.
Also, after what @AuntiePam said, I couldn't help noticing Virginia Mayo's insistence (really her director's, of course) on pulling her blouse off one shoulder all the damn time. I was also delighted to see, as the "literate" henchman, the great dancer James Mitchell, pulling off a straight acting role with total aplomb.
I may take a little break before I Died a Thousand Times; there are other things I want to see, and Jack Palance isn't a huge magnet for me. But I've watched the main titles, and one curious feature already stands out to me as a musician: it was scored by the same composer as Colorado Territory, David Buttolph (using the same orchestrator, too). So I assumed that Warners was just economizing, reusing the same tracks -- but no! at least the main title music is totally different in all respects. Is there a story there, or just coincidence?