Painters!!! they dont go out of their way to be awkward but probably get pizzed off when they have extra filling etc to do because of genuine bad plastering.
as regards to no key on the surface thats their problem. (as it is ours before plastering) They are sposed to prep a surface before painting it, i cant see a site manager pulling you and saying you need to trowel less hard,what happens if his doors are too smooth to paint all we have to do is provide a seamless finish with no abrupt changes in flatness or marks of any sort. balls to the painters let them find their own way to make more money