I think its a shame, disappointing and can make things more difficult for those of us who stay within our scope of practice. Often times clients come to us with different thoughts of what services we can provide. Sometimes this comes from experiences they’ve had with other trainers, gyms, programs, etc. I try to explain to them upfront my scope of practice as laid out by my certifications (ACE personal trainer and health coach). If they want something other than what I offer, I refer them to a dietician who can give them a more detailed plan. Most of my clients are ok with this once they understand why I practice the way I do (liability, education, etc).
Like many of the others have said, in the end, staying true to the professionals helps ourselves and our clients.