I'd avoided this thread, but I have a couple things I'd like to add...
First off, on the comment "these days, you do whatever you can to save money," please realize that doesn't apply to everyone. There are people (like myself) who put EF in their yearly budget, so (a) aren't going into debt just to go and (b) intend to splurge a bit, as it IS my big annual vacation. No, I don't want to throw money away, but I will spend a bit more to be comfortable.
... Which leads to the second point. I (for example) will not share a bed with a stranger. Period. I don't care how big it is, etc, I just won't do it. To add to that, even with most friends, I am not comfortable sharing a bed. That's the culture I grew up with, and that's my comfort level.
The US is often accused (rightfully) of ignoring others' cultures. To look at someone who says "look, I'm not comfortable with this" and say "get over it" is to ignore their culture as much as we are guilty of over here. If you grow up in a society where that just isn't done, telling someone to get over it just doesn't work.
To tie those together, I will personally go so far as buying two memberships if that's what it takes to get a guarantee of a bed to myself. Now I know you you don't have to go so far, but I know I am not the only one who feels that way. I don't envy the EF staff having to do all the bed assignments, but perhaps you can add a checkbox to request a double-bed room. If you are worried that everyone will check it, defeating the purpose, add a €10 or so surcharge for it.
As EF becomes more "multi-cultural" with non-Europeans growing more common, I suspect some of the US's (and others) prudish issues will come into play. Yes, I know I'm no longer over here. That still doesn't mean I can change my personal comfort level as I ride the plane out.