Add to this the anonymity of the internet and you get beggars and panhandlers. In my opinion, any account that asks other members for donations or payment should have their account deleted and IP banned. Mods should get on this.
What about Bitcoin enables easy and convenient donations? Should the mods delete posts of people trying to innovate for you that can be supported with mili-BTC? What about a good portion of the actual "panhandlers" having been attracted by a culture of people that donate easily (anti-greedy one could say)?
If you want to innovate you can do it for free. If you want donations you can link to your site where people can donate to you. Adding a btc. Donation address to your sig is just vulgar.
Anyone with a btc address as a sig should be banned.