JS and frontend are terrible and you'll hear this loudest from frontend people themselves. It's an entire industry built purely around the inertia of an unexpectedly wildly successful product.
I think it's worth noting that the Web ate software largely because the ergonomics for new devs are vastly superior to building native apps, and can be used cross platform without downloading binaries. What language is easier to get moving in? If writing cross platform native apps was as easy as using a single html file with a script tag, they would be more in vogue.
To accommodate the greater scope of the web the language has evolved. It's fast, supports multiple paradigms, and never makes breaking changes, so your code will run the same 20 years from now.
Is this a real issue? I doubt the average new coder needs to worry about supporting 20 year old browsers today. I've never worked at a company that needed to support ie8 or whatever.
These are orthogonal. You can believe software is important and a great area to work in, and still think JS and frontend is terrible. In fact, the two are often correlated!
If you think frontends, as a general category, are terrible, and backend software, as a general category, is more "serious", "real", or "important", you have precisely the mindset that produces theoretically useful gadgets that are ruined by poor user interfaces.
That's not the point OP was making. On the contrary, you have to believe that frontends are important to be really mad about how terribly they are made.
In general, I think any engineering community that congregates around a particular set of issues is just trying their best to address their needs and build solutions to their problems, and it's important to respect those. Rather than being dismissive, exposure and cross-pollination is how we lift the boat together.
Just because it’s terrible doesn’t mean the haters have to suck at it. It makes the opinion more valuable if you’re good at something and then criticize the bad parts.