I guess it’s the graphics and the weird keyboard combo? Because otherwise I don’t really see what’s the issue. It was so influential and good when it came out that you can get into actual arguments if any successor games are actually better than the original series (disregard the remake).
It’s basically still top tier stealth game, but the keyboard interface is weird as fuck initially. But you get used to it within hours, if you want to.
The graphics might be insurmountable for many people.
That’s always been the craziest thing to me about the US police system. In Finland the police is not legally allowed to lie to you about facts. They can lie about themselves and whatever, but not wholesale invent out of the thin air and gaslight people into believing that they did something.