How is the project named? Is it something reminiscent of the function (like PaintShop Pro, Photoshop, Internet Explorer) or something entirely random, forcing more cognitive load on an uninformed user (Gimp, Firefox, Juice)? Does it have a newish, edgy name to give it that extra sizzle (pantyshot, upskirt [zdnet.com]).
Thankfully, nobody ever game a dumb name to a piece of technology unless it was open. And nobody ever had to download the MSVCRT redistributable libraries, or install a Java runtime separately for a piece of closed source software, because they never depend on 3rd party packages.
Nobody would argue that there isn't a heaping spoonful of shittiness available to you in the open source world. You just have to accept that there are a million closed source apps out there that taste just as nice, despite the fact that they never released the source code. It's not really an issue of closed vs. open. It's an issue of limited resources and dumb ideas. I'm posting this from Windows 8 at the moment. As much as I can find to complain about KDE (and egad, so much...) I can find just as much here in proprietary land.
I'll grant documentation tends to be worse in open source as a general rule. But, if you ever wound up depending on some obscure closed source widget with a lone developer who doesn't fully share a spoken language with you, you will see documentation just as useless. Though, getting a thriving community of good technical writers interested in the open source movement would be a good things.