and if every1 did this no grps would get filled, as you would have 0 sign ups as every1 would be listing their own grp
What a pointless argument. You go from one non-existant extreme to the other.
Well if nobody posted their key everyone would be on quew and no groups would be formed. Would they?
The reality is that the ammount of keys posted, and the ammount of people quewing is a dynamic balance. The more you wait in quew, the more incentivized you are to post your own key.
And that changes in time (with tuning), with spec, even the day of the week. Wed and Saturday evenings are prime time. Less wait time because more keys are being posted.
It still changes nothing about the # of quews you can apply. If people post more than 5 applications, then key-posters would be overwhelmed by the ammount of applications.