I know of 6 schools that are now offering Introductory Flights of these schools two I know well.
They both started doing them because instructors have left for the airlines and they are unable to find replacements and I think that's only going to get worse as the number of instructors coming through is being far far outstripped by the number going to the airlines.
And if its done properly how is this a problem?
Also some of the best FI I have been trained by/worked with have been 'hour builders'.