For more discussion on the problem with consulting and education (which can be replicated just like software) see
Please Stop Using GNU Licenses
Hypocrisy alarm... Richard Stallman charging money for (restricting) speech:
A typical GNUtard will argue "but it's not about cost, he's not restricting speech, he's just demanding you pay him a big lump sum before anything comes out of his mouth, there is no restriction there, none whatsoever, he's just asking for a huge amount of money so that the words come flowing out of his mouth only after thousands of dollars come from your wallet - no restrictions there - he's not restricting speech. no no it's not about cost you see, even though GPL 2 says "must be licensed free of charge" and Stallman says "don't buy a house because it costs money" (quote on gng front page).. No, no, this has nothing to do with money."
(At this point you fall over laughing at their hypocrisy and 1984 George Orwell Doublespeak (newspeak)).