- Ordinary people aren't as capable at role-playing as us role-players; they are less imaginative and prefer passive entertainment.
- Anyone who doesn't want a lot of math in a game is stupid; we don't want to play with them, anyways.
They may not be expressed in these exact words, but I've certainly seen these put forth in one form or another. Sometimes the "passive entertainment" claim is expressed not as a lack of imagination but of dedication; ordinary people would just rather be passively entertained and don't want to make the effort to play D&D. And sometimes the math argument is expressed as "we don't need to reduce the math, because people actually love math. Look at all the other games with math involved!"
I don't buy the "passive entertainment" claim because it assumes that someone who watches a lot of TV, for example, would never ever do something more active. It's confusing what people do to relax alone with what they do when they socialize. People don't socialize passively; they ask questions, they offer stories, they respond to each other. Even watching TV with other people is almost never passive; during commercials, they ask about bits they didn't get, they compare what they just saw to other things they've seen, they talk about possible in-jokes, or other stuff the actors have been in, they speculate about what might happen, or what could have happened if one character had done something different. This kind of interactivity goes on and on, and it's very common. I don't think I've ever seen anyone who didn't do that.
And, at a party, when people are gabbing about what they'd do if they won the lottery, or what they'd want with them im they were stranded on a desert island, oe what their favorite superpower is, they get quite interactive as well. It's my argument that people are practically role-playing already; they're just missing two things: a continuing character, and continuing challenges.
Now, the math argument is what I hoped to specifically counter when I talked about distrust of system and the insidiousness of buffs. Basically, the problem with (many) RPGs is not the presence of math, but the focus on math strategies, as well as on other metagame strategies. But let's look briefly at math in games. I do not want a bunch of math in my games, and turn down requests to play games that I see as having too much math. Is this because I'm afraid of math? No. I was very advanced in math in school, and I still do most math calculations in my head instead of on paper. But even if I were a CPA or some other math-heavy professional, that wouldn't mean that I would want to play a math-heavy game outside of work.
I think that, behind the arguments about keeping math in RPGs, there's a lingering fear that, if you admit there might be too much math or inappropriate math in a game, you might be ridiculed. After all, only stupid people refuse to do math for fun! That would be the only reason!
RPG design arguments are often nothing more than a game of "status chicken", with each side being afraid to be seen as the guy who won't do X in a game because then they'll be admitting they're stupid.