You need to go to better hotels. I've been traveling the past 2 years multiple times a month and all my hotels have TVs with HDMI.
So much depends on how new the hotel is. I haven't been staying at fleabag, low-dollar motels, but I haven't been staying in a lot of new hotels. I was at an Embassy Suites in Portland for over a month in 2007; all the TVs (at least in the 6 or so rooms I saw) had composite connections. I've stayed at Hampton Inns and Holiday Inns (plus many comparable hotels), all of which had 4:3 CRT TVs with either composite or RF connections.
The only hotel I've stayed at that had modern TVs was a brand new Candlewood Suites, which had cheap (but serviceable) 27" LCD TVs. However, even that was a fiasco. They set their TVs to some bad (I mean really horrible, worst I've ever seen) stretch mode and gave you the cheapest universal remote possible, with minimal controls. I had to ask at the front desk to get the right remote. Furthermore, they had cheap DVD players in each room, all connected with composite cables (not component). To add insult to injury, they hooked all the red cables to the red component (instead of red/right audio) outputs, so you didn't even get decent stereo audio (obviously, I fixed that for myself and several others staying there).
My point is that a lot of hotels do not have HMDI or component capable TVs. And when they do, they don't always know what to do with them. Counting on the AppleTV being a good hotel solution is a crapshoot.
One other thing about hotels: they often have really mediocre internet speeds. At two recent hotels, I ran Speedtest and got download speeds of less than 1 mbps, not nearly fast enough to get a decent NetFlix stream.