We don't expect med students to have spent their teenage years doing experimental surgeries on their friends. Or accounting students to have taught themselves by doing accounting for a major business in their after-school time. Nor do we expect a microbiology student to have spent their childhood experimenting with infectious viruses and bacteria in their garage.

I think we expect that in comp sci just because many of us did happen to grow up doing that. But it's a weird and unusual expectation, and probably not a good one.

It also certainly wouldn't have been expected a few decades ago. You just wouldn't assume that a kid had a mainframe in their house to have learned on. Now that PCs have been around for awhile, we make that assumption, but again I don't think it's a good assumption. Certainly not for the less-affluent, nor the younger ones who grew up with smartphones and tablets instead of a PC.

I think there's also a bit of disconnect in what the purpose of the major is. Actually having a separate 'Software Engineering' major is relatively quite new and generally, Comp Sci was what everybody took if they wanted to learn to work on software. But now some people think it's a totally academic thing, while others think it's industry training, and that always confuses the discussion. But even in spite of that, it's just a bad assumption/expectation.