So your belief is that if brand A can make a camera at $2000 and brand B can make an camera at least as good at $1495, the majority of prior brand A customers will stick to brand A?
Why? Due to existing investement (perhaps only a heavily invested minority), or due to being brainwashed?
I like to think that there is at least some "rationalism" in the market, where people choose the supplier that has the best price/performance ratio.
There is also momentum.... Someone who is just getting into cameras may make a very different decision than someone who has legacy equipment.
Take me as an example. I shoot a 60D, have several APS lenses and a few APS-C lenses, and I am going to upgrade. Let's say I decide to go FF and let's say I have around $3000 to spend. I might look at a Nikon or Sony offering and decide that it's a better body for my needs than a $3000 Canon body, but then I would need lenses..... and there lies the problem. It can never be an equal comparison when I ask what $3000 Nikon body PLUS lenses will work as well as a $3000 Canon with a bunch of Lglass thrown in the mix for free.
When I started with Canon coming from a Sony DSC-F 828 compact cam, the reason to switch was a) I dropped the sony, but b) was unhappy with the IQ. While saving up I decided to go back to SLRs (had a Contax 139 Quartz 30 years ago) and chose Canon a) gut feeling b) IQ c) price. Purchased an EOS 30D. While growing deeper into nightphotography I decided to save up for a 5DII, skipped it due to the reported AF issues, and bought the 5DIII last August. So, I changed brands, but in my case did not loose anything, as the cam was the loss in itself. But, according to sensor tech, it sometimes pays off to stay with the brand and go for a walk through the "desert". Although, at the end of the day, if the mirage of a perfect cam becomes real, recompensation for the wait is tremendously high