Because TVs sound like the speakers are made from tinfoil.
My $2,000 TV sounds terrible. My $300 TV sounds even worse. It’s kind of ridiculous. I shouldn’t need a whole home theater system just so I can watch TV in the bedroom without it sounding like my favorite characters sound like they’re on the other side of a tunnel.
The reason is pretty clear: most people buy TVs in club stores or department stores, and the thing that attracts them is a bright picture and a low price. All other things being equal, people want smart TV features and a relatively thin edge bezel, but everything else is secondary. Even the thickest TV is plenty thin from front to back, and unless you’re willing to really spend a lot of dough you’re not going to consider features like HDR, 4K, or adaptive dimming. It’s a big screen at a small cost that drives sales.
Notice that nowhere in that paragraph did I say that people buy TVs that sound good? The sound is usually off in the store, and it’s a fair bet that 95% or more of TVs are bought without even listening to them. Sound doesn’t enter into the conversation until you get home.
At this point, maybe it should.
TV sound has never been terribly good; when televisions came as part of large consoles with “hi-fi stereos” built-in, the TV broadcasts were poor, and by the time that stereo and Dolby Digital became part of the TV watching experience, TV speakers had shrunk to the size of a baby’s fist and sounded like it. The standard trope today is that if you want good sound, get a sound bar. They’re not that expensive or obtrusive, but still, why?
Small speaker size doesn’t mean that the sound will be terrible; Bose speakers prove that. The issue is that Bose speakers are well-engineered and that costs a lot of money. There just isn’t enough profit in a cheap TV to justify it, and I guess the feeling is that if you have an expensive TV you are probably hooking it up to something else anyway.
I just wish there were a happy middle, where you could have a TV that sounded reasonably good without piling on the extra gear or without piling on the extra costs. I guess that’s too much to ask.