Used to own a C150 many moons ago. Never found it to be particularly nasty in stall/spins. Good little bird actually, very economical to fly, honest 100 mph cruise on 5 gph. I agree the flap system stinks especially if you're flying a clapped-out flying school bird that has a wonky or missing indicator.
The 40 degree flap setting could be fun for short landings, but it could also bite in a couple of ways. First of all with that flap setting you could land in a remarkably short distance, on a small grass strip only to realize (hopefully not the hard way) that you didn't have enough room for that little 100 hp Continental to pull you out. Secondly, in a go-around, you required fairly large forward stick force to keep the bird from pitching up, plus it would not climb with 40 deg, which was all drag. So you had to get rid of 20 degrees quickly. See comments about wonky indicators...sometimes you could be surprised at going too far, losing lift, and watching the trees at the end of the runway coming up, and suddenly wishing for another 100 hp.
Students have also been known to forget to milk off 20 degrees in a go-around. I flew out of a place for a while that had a house off the end of the airstrip. A student from another field came in and did a go around but forgot to milk off 20 degrees. He went around the house, not over it...fortunately he or his instructor realized the mistake and they eventually got airborne, but I suspect a change of underpants was required upon return to home base.
There were a few spin training related accedents due to jamming rudders due to a faulty rudder stopper. Might have something to do with the stats.
Overall the C152 is a nicer little aircraft except for the 28v electrics (no more jump-starting with the car). The O-235 is nicer, not as prone to carb ice as the O-200, and the bonus for private flyers, it has a 2400 hr TBO vs 1800 hr on the Continental. This reflects itself in the selling price, at least this side of the pond, where a 152 will fetch a good $5-10k more than the equivalent C150. Plus as is pointed out the flap system was simple and fool-proof and you don't really need the extra 10 degrees of flap.
I liked the 150 a lot though, had loads of fun without spending large wads of money, and sometimes I daydream about selling my Sundowner and buying a little 150 to fly off into retirement...