Few people feel strongly that a chip running Linux makes a TV worse. What they object to is when the manufacturer controls the TV rather than the owner of the TV. Modern smart TVs override the users' desired by, for example, showing ads. It's even possible these chips will eventually be responsible for copyright verification.
This would be fixed if it was possible to modify the chip's software and easy to install alternate OS bulbs.
Exactly. Were smart TVs to come with OSMC pre-installed, where I have full root privileges on the computer, then it would be a fantastic thing. But since they are instead designed to spy on the alleged owner, to report usage, to download unskippable advertisements, then smart TVs have instead become an abomination.
There's a very real opportunity here for an open source project that takes on the task of doing an alternate kernel/distribution/applications for smart TVs. Big job, and likely to take a while before getting caught up with newer SoCs etc.
But it's totally doable -- it worked for e.g. OpenWRT on SOHO routers, sat receivers, etc.
This would be fixed if it was possible to modify the chip's software and easy to install alternate OS bulbs.