Prior to cell phones most people had 2 phones in their house and never replaced them.
Your 1995 TV set is probably 100 lbs too. TVs are often limited by where cable is.
Most your argument makes sense. I do think the key issue is that TV will be the first device that starts the rotation of Apple from HW centric to Content (or Experience) centric. Opposed to now, Apple is building out content to make the HW they sell more valuable.... this will be where they sell TVs at near cost to sell convenient access to Apple content and experience. It's the ultimate 'docking station' for iOS/iCloud.
Think of it another way... Once you get an iOS TV that makes it painless to slurp $2.99 episodes of Survivor and 1st run movies, you're locked into iOS devices throughout the life of that TV.
Yes people of course will replace, but Apple has to really really do something EXTREMELY compelling to get people to upgrade a TV! A phone, just toss out or recycle (a lot of the time for actual $$$$) whereas a TV (in the UK at least) cannot just be thrown or easily recycled (and when you can recycle you usually have to pay to get it done!).
They may release their own TV, but I cannot see it selling in the millions their other devices sell like. And people will not likely fork out $1000+ for a 45" TV in my opinion even if it is a fancy new shiny Apple iOSified beauty, some will, but the average consumer, who might pick up an iPad or iPhone I don't see doing it...
It's just my opinion, and after all of these rumors I am inclined to certainly think they want to build a TV set, but I just don't understand why as of this moment. Obviously Apple have something that they believe is the future, that they believe will be unique and something that people will feel that they need and I hope that we find out what it is!
Apple could surprise us and build a series of fantastic 4K displays w/ multiple HDMI inputs / 1 HDMI output (surround sound AV receiver output) and with a hidden dock for an AppleTV box that could be upgraded when needed/wanted...
They could, but 4k is still a few years away from being in the $2000 price range (I believe) so if they did I'm not sure how small a market they are going to be attracting.
Unless of course, the Apple TV (box) could add the majority of features (apart from things like gesture or something) to an already existing TV. I want to see what they might have in store for people, at the moment I personally can't think of what it could be (am not the creative type lol).