YANBU, OP. It's true that the underpinning problem is political but there are a lot of scammy practices in dentistry and a terrible attitude towards NHS patients (not that there are many anymore). A registration to practise dentistry privately in the UK should be accompanied by an obligation to provide a certain number of hours to NHS patients imo, and, ideally, to do it with a good bloody grace considering the NHS provided the guinea pigs for them to learn their craft on when they were training.
I've been an NHS patient for years and have had dentists actively try to scam me by saying a tooth needed complex root canal work done that required a private referral to another practice (while that other practice was referring NHS patients in the other direction) only for me to ask instead for an NHS referral for surgical extraction at the local hospital, where I was told there was absolutely nothing wrong with the tooth at all. That happened to me and also to a friend.
Even more commonly, I've sought help with a tooth I knew was collapsing, to be told that there was nothing wrong with it except some "dental concussion" (which appears to be coded dentist-speak for "we don't give a fuck because you're not paying") and ended up not being able to eat on one side of my mouth for months on end until said tooth finally did collapse on a grand scale. That's happened twice, most recently yesterday.
This morning, I phoned for an emergency appointment, to be told that my dentist no longer offers NHS work, even though I'm an NHS patient. No communication to that effect at any point before today. I was offered my choice of a 12.30 or a 3.30 appointment, which are the last appointments of the morning and afternoon respectively. At £35 it didn't seem so much worse than the NHS charge so I took the morning one.
Turns out the tooth needs work (no shit!), which couldn't be done then and there "because it's lunchtime", so I was asked to come back tomorrow, when I'll have to pay all over again for a proper appointment. So basically, they're running a nice little scam in appointments that are too short to do anything in at all, at £35 a pop. Nice work if you can get it.
Nobody - not even this bloodsucking Tory government - is making dentists behave this way. My anecdotes involve three different supposedly NHS-inclusive practices in a 1/4-mile radius, so all common sense suggests these are commonplace activities, but it's very difficult to prove dishonesty when there is also a clinical context and practitioners can fall back on a pretence that what they chose to do or not do was in the interest of the patient as they perceived it.
What is needed is someone with the energy to collate a vast range of data and present it in a way that will grab political attention, so if there are any investigative journalists on the thread, now would be a great time to introduce yourselves!