Either they've been fooled like everyone else, or they're just sick of hypochondriacs.
How many GPs would discover a tumour and say "Don't bother going to the hospital, you need some homeopathy".
That's all well and good until you get cancer and decide to "treat" it with homeopathy instead of going to a real doctor.
The very principle of homeopathy, dilution, is unscientific.
"The big drug companies don't want you to know about this..." etc. etc.