I think that when some doctors make statements like that, the key is to ask them why they believe that way. This will give you a sense of whether it is ignorance, or an informed opinion backed up by recent studies or extensive personal experience.
For example, soon after I had my resurfacing, I was talking with a friend who is an older orthopedist, and who, in his time, was easily one of the most respected orthopedists in the country. He commented that he was sure that I would have to give up my summer windsurfing career, because the amount of flexion involved would lead to a high risk of dislocation. His opinion was based on 40 years of being a leader in the field of smaller head THRs and their relatively high risk of dislocation. However, he had no idea about more recent studies showing that the dislocation rate for resurfacings is near zero. I continue to teach high level windsurfing in the high winds and large surf of Maui, and have had absolutely no issues with my new hip from this.
This man is no dummy, and is easily one of the leading names in the history of american orthopedics; but he was very clearly not a good source of information on the small field of modern hip resurfacing.
Another friend who is an orthopedist and who is considering a resurfacing for himself, said that he believed that I, as an informed patient, really knew more about resurfacing than most orthopedist, not to mention general practitioners. This in no way means that I know a lot, it just means that a lot of them know very little.
It is always good to hear what various medical practitioners have to say, but it is also good to ask them what they are basing their opinions on.