"Any new product they could introduce would be likely to cannibalize their existing products. After all, one reason for a man to want to use a reversible contraceptive is so his partner can stop taking the pill."
Little economical incentive to cannibalize its own market. That makes so much more sense than conspiracy theories preventing this from happening. I disregard real "scientific barriers" here because I believe capitalism would have driven science to where it wanted anyway -- hell, there's very little stuff in the world that won't see any meaningful progress after 50 years of research.