All true. If you are a pro looking to get paid then this is not for you. If you are looking to collaborate and you like drumming and you like recording and you (optional) like the example song, then get in touch. You will not be taking money from the pocket of another drummer, because this is not a paying session.
Many thanks for the positive interest from those of you who have replied so far. PM me if you want a drumless version of that demo track to have a go at.
What you're doing though is giving the impression that drummers shouldn't get paid to spend time learning parts, playing, learning to record those parts and all of the equipment that goes along with that. I might perform for nothing on a personal project - Hell, I release my music for free - but I would never ask anybody else to do that if I expected something to be of a releasable standard.
What you're saying is that it's good 'exposure' and that they'll get a 'songwriting credit'. Frankly, if it's good enough to be exposed to others and the song writing credit is worth a damn, you should &^%$ing well be paying them to perform on the track. You're dragging down everybody's pay.
The other one that gets me is being asked to play/tech for nothing for a charity event. My litmus test is whether security and catering staff are being paid. In which case, they can damn well pay me as well. At my hourly rate. On my terms.