What is the purpose of account collection

I've now given about 5 invites away on this forum in the non-VIP giveaway section a while ago.

I've got more invitations available but I'm a bit reluctant to give them away again...why? Well, all except one invitation seems to be used by account collectors. So someone who creates a username on the tracker and then does nothing, not uploading or downloading even a byte of data. The other user has gotten himself banned because he probably downloaded a non-popular file and didn't meet the ration requirements after a certain period.

I'm struggling to find a logical explanation for account collection, except for wanting to sell the account at a later stage.
Pretty difficult to avoid the collectors I presume, but still...how maybe?

I'd say probably to hang out and wait for the possibility of invites and then to try to trade up the invites for an account on a more desirable tracker.