In my personal opinion, which should not be construed as the opinion of any instructor, shop, or agency, an instructor who tells a DM student to do bounce dives to meet a prerequisite for certification is a bad instructor. I would consider any such instructor to be doing a disservice to himself, his student, and all those with whom the student will work in the future. (You can be God's gift to diving, but if you don't have the dives yet, I am sure you'll be even better once you're there, and gaming the system is not a lesson anyone should teach such a great diver as you.)
Of course, I may have an overdeveloped sense of honor and duty, but if I were to ever see a logbook such as that, I would fall back to the "Dives shall be varied in environment, depth, and activities." line from the NAUI S&P manual. As I interpret that (and I will certainly tell prospective leadership-level students before they begin), all dives done to "minimum loggable dive" standards that I believe were for the sole purpose of inflating a logged dives count will be expressly discounted. I won't be harsh or anything -- even though I find such dives well outside the realm of good and responsible diving, I will not additionally penalize the count of actual dives once those are eliminated. :biggrin:
I've actually seen a diver who met the logged dives count who was told that his dives were not in sufficiently broad conditions to be acceptable. He had to go out and dive somewhere other than our checkout trips and Cozumel in order to be broad-based enough to make an acceptable DM candidate. This, I firmly believe, was far better than the diametrically-opposed example of logging to-the-minimum dives just to have some arbitrary number.