There should be no reason for a significant amount of blossoms to fall off if one is taking care of the plants properly and there is sufficient pollination.
Yes, every single flower will not set fruit, but hot and sweet peppers have the ability, under sufficient care, to set over 90%
Proper plant nutrition is key, giving the plant the right amount of what it needs at the right time.
And hey, it's actually pretty easy. Too many people get caught up in what kind of fertilizers their using this and that, brands ect. and far too many people over care for their plants!....Its a PLANT....it will grow. Your not going too the moon here...your growing a plant.
So what to do...for peppers....In simple terms... use high doses of nitrogen in the beginning growth phase with lower but still adequate ammounts of phosphorus and potassium. Make sure your plant gets the micronutrients it needs as well. Any complete fertilizer will do....then when you see flowers starting to form pick them off, then start to apply much much lower ammounts of nitrogen and much high doses of phosphours and pottasium to get those flowers to form and set. Use common sense though and don't over fertilze the plants, work your way up slow on the doses... And peppers love lots of calcium, make a note of that.
YOU MIGHT BE SUPPRISED HOW MUCH FERTILIZER A PLANT CAN HANDLE