I understand that the forum does not currently need additional money, so theymos has no reason to lower the threshold to entice more people to donate. A few businesses still donate when they start doing business here to get a donator tag. You are free to donate any amount that you wish to the address found
https://bitcointalk.org/donate.html Even though the forum might not need any money at this point according to you, it would be a nice addition to have new ranks introduced that can be obtained the same way as is the case with VIP and Donator levels.
It's obvious that the majority of the people nowadays aren't really interested in donating. Their only priority is the rank that they will obtain at the time they "donate" to the forum.
That's why I believe one or two extra ranks can turn out to be an interesting addition for the people here, and most likely also for the forum as it generates an extra bit of revenue. It's basically a win win for both parties.