There's no such thing as bad brick, but even if there was, the fault lies with the contractor and his poor assessment and preparation of the surface to be painted. I'd say you have a really good case against this so-called professional, and should consider taking him to small claims court if he maintains his refusal to address the problem.
At the route, this sound's like an adhesion problem. Was the brick pressure washed to remove the old paint? If so, did the contractor wait a week or so for it to dry out? Brick that gets wet, stays wet for a long time and paint doesn't stick to anything that is wet. Secondly, did the contractor us a primer? That would have been a crucial first step as only primer has the adhesive qualities to stick to a subsurface like brick.