I think to a degree the brands lure you into a feeling of trust that you are investing in a quality instrument.
Of course the flip side is that part of your money is not going on the quality it is going on the brand.
I always wanted a Joe Satriani signature model Ibanez guitar. I liked the design etc. When I looked at getting one I realised you could get another guitar of better quality for your money that was not a signature model.
So in some respects I think that the brands can take advantage of their selling power and probably the lesser known or respected brands actually have to make a better product for the money to try and compete.
I would still love a Gibson Les Paul though. I have never owned even this style of guitar before though I know I would love it.