I find this theory intriguing.
Unfortunately for you, I'm going to have to side with your roommate on this one.
I love ELO. Listening to them is like eating a big piece of candy. It's sweet, it makes you want to move around a lot, and it will probably rot your teeth if you listen to too much. It's incredibly obvious that Jeff Lynne was probably as big of a Beatles fan as Foreman and I. His Beatles-esque pop style is just...well, it's just great is what it is. It is most often sunny, laden with harmonies, and composed of great hooks. Further, Lynne was a perfectionist. Listen to "Turn To Stone." Every single note in that piece was placed with precision. He was probably a Nazi in the studio, making sure every band member lived up to his exacting specifications. Oh, and speaking of the studio, Jeff Lynne followed in the footsteps of his idols, the Beatles: he preferred the studio to the stage, feeling that the former was more conducive to his creativity.
Now let's look at Arcade Fire. I love these guys too. The comparisons and contrasts here are a bit difficult, seeing as they've only released two albums, but we'll see what we can do. Arcade Fire, to me, sounds constantly on the edge of sonic self-destruction. Their music contains an energy that their songs seem barely able to keep in. I mean, listen to the end of "Power Out" when Win Butler starts screaming, the guitars start going...it sounds just about ready to burst. ELO never created that feeling with their orchestral masterpieces. Further, I have read from a number of sources that Arcade Fire seems to get a great deal of pleasure from their shows. I've heard that the concerts are filled with energy that make them an amazing band to watch. Oh, and also, Arcade Fire doesn't drench their songs in keyboards and strings nearly as often as ELO. Finally, Win doesn't have nearly as good ("good" being used to describe technical musicality, not emotional conveyance) of a voice as Jeff...not to mention that Arcade Fire's only occasional use of vocal harmony isn't close to how much harmony ELO used.
So, while I don't think you're crazy, I don't think you're completely right either. I did, however, find a list of songs
that do sound like ELO. Check it out. Oh, and by the way, a quick search on the Googles turned up a few people that agree with you.