>why is everyone in such a rush

because they aren't Ivy League educated and world renowned professors who make millions working for Google. Those books prey on desperate people looking for a chance to break into one of the few industries left that provide a decent living

I think it's just unrealistic expectations about what learning is like, how long it takes, and what you do to learn.

In part, perhaps it's from the educational system which curiously enough isn't geared particularly well toward learning. It used to be geared toward the needs of teaching (which is not the same as learning), but lately it's been geared toward passing standardized tests. Someone going through such a system might be excused for thinking that the way you learn something is by cramming facts until you can repeat them once and then forgetting the whole thing because that test isn't coming back.

I think there're some good and positive reasons including:

1. If I'm going for a full stack interview soon, having a quick look/update would provide a good refresh before digging in deeper.

2. Someone wants to compare between different aspects/features of different languages, some quick learning would definitely provide a good sense of differences.

Most jobs forces people to do things as quickly as possible, and that results in trying to learn things quickly. I see nothing wrong as this is being part of adapting to the environment.

Tbh. For me it's like a personal and professional deadline. You expect to learn/to be good at something in a short period of time, while it's expected of you to deliver good quality (consulting, product, support or whatever it may be), and this "cannot" be done unless you know your shit.

Like mym1990 pointed out, no one likes to be new/bad at something, or maybe that's just me.

If the programming is merely a toolkit for something else, I want to be productive ASAP, with minimal distraction from the main goal.

Even if it is the main tool for the main goal, we still want to get there soon. And in this case, 'there' includes being able to get to levels of deeper mastery, so accelerated learning of the basics with minimal wheel-spinning helps.

OTOH, if it is a pleasurable hobby or pass-time, then sure linger for a decade with all the trivia, and enjoy the heck out of it!

Money problems.

People want instant gratification and people also don’t like being bad at something for long

Because they, correctly I think, subconsciously sense that programming could and should be much easier than it presently is. The ghost of Hypercard looms.