Pay to leech refers to paying to download without contributing anything. It's a pretty common phrase in the piracy and specifically BitTorrent scene. It's not ONLY pay to leech, but pay to leech is an option.
You will notice that the higher tiered trackers do not give this option out for donations.
Listen you have to pay the bills. I get it. I don't think your site is terrible by any means, but their are some things I don't agree with. It's your site. You do whatever you want with it. It's obviously successful.
I'm just offering my opinion. I've been around the block and have been an admin of a tracker before. I've been using private trackers since before Oink was around. I've seen my fair share of terrible sites and amazing sites. You run a good entry level tracker but don't assume everyone is attacking your. It's just 0s and 1s. Much love.
I've been using private trackers for 20 years. I just know what I like.