It isn’t exactly news that photographers are not necessarily good businessmen. Just look at Magnum, back in the late 50’s you would have expected them to be swimming in cash with Robert Capa at the helm with people like HCB there? According to the book I’m reading at the moment Capa saved Magnum several times by borrowing $5000, throwing a massive party and getting $10000 in contracts from that party letting them live on. They’ve apparently never been financially sound and their corporate lawyer was working for free for essentially 30 years because he idolised them. Now if this is a collective of some of the best photographers the world has to offer imagine if you were just as rubbish at business but not a world famous photographer? Disaster.
Mini sessions are not what anyone wants to do but they pay the bills provided you can get enough of them. They can also lead on to further contracts in the future provided they like you. I don’t think it is a good idea to do mini sessions as your main source of income but to pay the bills, why not?