Well, I have to say that I have yet to meet any of these 'critics' at a live gig.
I'm sure my friend, guitarist Ken Gilbert, with whom I do a good proportion of those gigs that I play these days, would back me up when I say that the only comments we get from our listeners are complimentary - they tell us how much they enjoy the sort of music we are playing and the fact that we use backing track is never, ever queried.
Backing tracks aren't a prop for a poor player. A poor player will not sound any better with a backing track than with live band. Backing tracks, used properly, simply provide the 'canvas' upon which a good player can work his or her musical artwork.