Can Tube Amps be Used for Home Theater?

Big mistake to leave tube amplifiers on all the time.
Tube amplifiers have large and dangerous voltages in them, and leaving them on, unattended is very dangerous. They need to be under ones' watch as at anytime a power tube may 'blow' and start a fire, or just plain scare the hell out of you. You would have to be crazy to leave a tube power amplifier on all the time.
They do not blow up all the time, but often enough to be really dangerous to leave unattended.

There are PLENTY of great sounding solid state amps you can leave on all the time.

Elizabeth is correct. Although I'm using a large tube amp in my 2 channel rig with HT pass through, I would never leave it on 24/7 for safety reasons. Also electrical costs and pointless tube degradation play a factor. Go SS for this project.

At one point, I was using all ARC tube amps for my home theatre. (I didn't leave them on all the time, of course). The system consisted of a very old Dual 75a that I have owned since the early 70's, a Classic 60 that was relatively new, and a large monoblock that I purpose bought to use as a center channel amp. (the woofers, a pair of velodynes, were self-powered).
The system sounded great with Snell speakers, but it was HOT after a few hours in the viewing room. I have slowly migrated away, first switching to solid state for the rears, then eventually all channels. I now use a large McIntosh multi-channel amp with oodles of power, and, at least for home theatre use, it sounds great. (My music system is not part of this theater system). I still use tubes in the audio system, but that's another story.