I am a vegetarian and agree with most of the article up until the very last sentence - "where would you have stood on the issue of slave labour" or words to that effect.
I feel like that confuses the issue and makes it easier to argue against - humans are very clearly different to dolphins and equating the two does noone any favours.
A side project doesn't need customers, a side project doesn't need money, a side project just needs to be something that you want to do. If it makes money, great! If not, it doesn't matter because you are doing it for yourself and noone else.