[Dewie]

If they don't feel smart enough, that is just going to be compounded by joining a programming community. Smartness is the status symbol to these (us?) people, so get ready for a lot of subtle and not-so-subtle comparisons of people's academic record, what tier of university they went to, what inherent hardness of problem's they have worked on, whether or not they started programming before they could talk, who is working with a language/ecosystem that are seen as intellectually inferior/lazy, whether they are part of the mythical "10X" ũbermensch[1] develeopr, whether or not school-work came effortlessly to them, and so on. No, of course the tone is not as obvious as "I'm smarter than you, or I'm less smart because X, Y, Z". But the underlying tone is clear enough. The best way in these communities is to compliment their smarts, or imply that they are smarter than you. The perfect way to insult them is to insult their intelligence. The common currency is brains.

If they don't feel smart enough, maybe what they mean is that they expect to end up on the bottom of the status hierarchy. And that might be a bit too rough to want to go through with. Especially if you have other interests, aptitude or talents.

[1] Yeah, umlaut-fail.