We tend to get much more mad at characters when their shitty actions are within our frame of reference. Like, nobody's morally outraged at Pennywise for eating children cause it's so out-there. But if he was rude to wait staff you'd be like "jesus, this guy's a real asshole huh?"
That's not at all what I think, of course the first thing is worse. But because the second is more relatable and within the realm of our experience, it produces a more viscerally negative reaction. We can watch horror villains murder people and think "oh that incorrigible old scamp up to his old bag of tricks!" because it's so far outside our everyday reality
I came here to say this. I don’t think it really matters how old he actually is because he looks 17 (when it comes to conceptualizing the age gap, ofc it’s creepy regardless). To Bella (the POV character) he’s 17 so to the audience he’s 17 and I don’t think it’d be perceived any different if he’s been 17 for 40 years or 100