As long as you make it clear beforehand that's what you want, then the photog can decide whether or not they're ok with it. I'm also a pro and personally I would love more jobs where I only have to deliver the RAWs as like the other guy said editing is what takes the vast majority of my time on most jobs, but I certainly also understand the other side of the argument.

Another way to think about this: if you were a chef and someone came to your restaurant and asked for the raw ingredients so you can make the food yourself, I don't think many chefs would allow that either.

Sometimes, you have to/decide to use techniques which might mean that the RAWs are pretty useless unless they also go through the specific post-process you had in mind while shooting.

With that said I know that many of my colleagues can be total dickheads in particular when it comes to the niches that deal with end-user stuff like family portraits, weddings etc, so I have no troubles believing you've had bad experiences.