I think it's a great idea, paid signatures add nothing to the site and only encourage useless posts. There are way too many people who post in every topic because it gets their post count up, the posts look useful but overall it really just adds to the noise.
Good luck getting glorious leader to make a change!
The idea that paid signatures add nothing to the site and encourage useless posts isn't true simply because you state that it is true. In fact, it is false on its face.
1) People who have no other way to earn bitcoins may choose that as their best (and only) option to obtain them. As such, they are more likely to remain and contribute to the site. Adds to site.
2) While some people are encouraged to make useless posts, that is easily rectified by a note to the offender or the sponsor. As the sponsor is going to only pay for substantive comments, once again, that encourages people to post substantive comments. Adds to site.
Taking away incentives to stay, contribute meaningfully, and build community, is not a way to better any site. Especially this one where the members are generally interested in bitcoin, and not just slinging websites that exist solely to sling websites that exist solely to sling websites that exist solely to create referrals and downlines.
And actually, it seems that convincing glorious leader to make a change took almost no effort whatsoever.