Each of these statements could equally apply to TVs (except, possibly, portability) and the fact that they haven't is merely circumstantial.
Yes, for the first 50 years of television's existence people tended to keep the same TV around for half a decade or more. But that's because fundamental changes happened between fifteen and thirty years apart - the switch from black and white to color, then the switch from broadcast to cable and satellite. The rate of innovation, and thus the turnover rate of individual devices, is increasing - just like with the telephone, which remained basically the same for the first several decades of its existence as well, until modern computer technology was invented.
Come to think of it the same thing is possibly true of desktop computers. My family was on the same computer between 1984/85 and 1993 - a Mac 512k. Then in 1994 or 95 we got a Performa 475. That lasted for about 5 years until I got a Mac clone - a Motorola Starmax 3000, which had a PowerPC processor. This laster about 2 -3 years. Then I built my first PC - that lasted for about two years. And each year since then I've used the same computer for 1 to 2 years at a time. The turnover period halved exponentially as computers got more and more sophisticated.
Add in the fact that good TVs are basically always made by the companies who are the Very Worst at software (Samsung most prominently), and you have a recipe for digital heartburn.
No thanks. Dumb TVs forever.
Also, to respond to another comment, there's no correlation between a TV being "smart" and achieving a simple A/V setup with a single remote and a minimum of hassles. Unless you mean a negative correlation. It's very simple to achieve single-remote nirvana with a dumb TV. Plus you're not stuck with a dumb company's remote and software; you can pick your own, because a dumb TV will work with anything and not get in your way.
Singled out for especially thorough beatings are those TV makers who put actual physical buttons on their remotes for websites that might be gone next week. Seriously? No.
Dumb TVs forever.
I don't think the problem is with Smart TVs, I think it's just the current execution of the idea.
That's why it's great for a cellphone to run a full modern OS, and why it's NOT great for a TV to do so. TVs last across multiple tech generations. They should contain the bare minimum of software needed to display whatever content you pump into them. Nothing else.