Very very often you can see a 0/0/1 group just...sitting there for 10-20 minutes. Doesn't invite anyone, nor does it go away. If you apply, you either get instantly declined or just ignored.
Either people start a group and immediately go afk for some reason, OR there are some trolls who do this on purpose because they get off at annoying people and possibly enjoying the whispers from very high rated and geared players asking why they are being declined. Or it's some guy pissed off at being declined, so now he makes a group just to decline people too.