I think part of the problem is that physical therapists are not upfront about the differences themselves. I'm sure they are fine for a massage but some would happily pass themselves off as physiotherapists.
I recently went to my local medical centre and asked if there was a 'physio' there. The girl said 'yes, I'm the physio'. Physio clearly is short for physiotherapist so I think she deliberately misled me. It wasn't until I was on her table that I realised that she was only a physical therapist.
When I asked her the difference I was told that 'we don't use machines on you, we're more hands-on'. I got the exact same answer from another physical therapist in my area. It would be much more honest to say that they don't study academically etc.. as Karlitob's post above highlighted.
This crucial difference was clear when I asked the 'physical therapist' about a certain well known condition. She told me it didn't exist and I was amazed and questioned her further. She told me then that she might know it by some other name. She should have just said 'my course doesn't cover conditions'. If I didn't know myself that it did exist and could be rectified I might be still going back to her and paying her a fortune for the wrong treatment. This woman is in a local medical centre with GPs!? I don't know how any GP would share a space with a physical therapsit like that. She also charged me €60 - more than some physiotherapists!
I also had some contact with one of the physical therapy training centres in Dublin. When I enquired about their library I was told 'the students don't use it, their training is hands-on'. That sums it up for me - physiotherapists all engage in evidenced-based therapy and would be constantly keeping uptodate with medical evidence for various treatments by reading academic journals and engaging in cpd.
There really needs to be greater regulation and public education around the differences between the two professions.