Not arguing against your general points here, just wanted to say that using a password manager (I use KeePassX + Dropbox) has made the 'invent password' part of the whole process that much easier for me.
Although, the fact that there are popular tools available to work around the extra cognitive load imposed with account creation and tracking is a very good sign that a free account is much more of an impediment to the general person than these sites seem to realize.
Also, it doesn't affect the fact I still don't want to give away my email address before I've decided a service is worth having an account for.
It's a shame, because I am interested in seeing what the service is like. The problem is that my interest is part driven by wondering how similar it is to my current technique (put on my "Glitch Mob", "Zack Hemsey" or "Carpener Brut" stations on Pandora), wihch means I'm interested if it's slightly better, because I'm not unhappy now. I am at the same time very likely to use their service if it's good, but unlikely to jump through hoops to find out, since I have a solution that to my knowledge works sufficiently, and I've even decided it's worth paying Pandora for. Not exactly the type of customer they want to keep from seeing their service in action.