I don't usually join guilds.
I don't think there is anything wrong with taxing, though.
Just as this games payment model taxes all players to play in order to collect steady income a guild should be allowed to do the same.
Having people complain about who is leeching or having members who contribute more demanding more say in where the money goes could be reasons why people would choose this method. Don't expect me to pay though because I'm a dead beat loser.
Cut him some slack guys. ^_^'

I hope you find some members and your guild prospers.