I actually consider all external keels to be more of a hazard than most
cases of blisters. In most cases, it is imposible to detect metal
fatigue in the keel bolts and even going aground softly can cause
failure in them. I think statistics will bear me out on this relative
comparison.
Sailing through thunderstorms intentionally is seriously foolish, even
being on the water when one is near is foolish compared to sailing on a
boat with blisters. Statistics easily show that the number of boating
deaths from lightning NOT originating from thinderstorms is very high
compared to those from blisters. I live in Florida so am very
cognizant of the risk of lightning. Last year I actually calculated
the risk of getting hit by lightning (a long discussion here) assuming
some reasonable conditions and was amazed at how high it was. A
susbesquent examination of insurance claims bore out my calculation.
Compared to lightning, the risk of blisters is nonexistent.
I can think of no reason why boats with serious blisters would get any
less use than others except in extreme circumstances, yet these extreme
circumstances cause vety few of the accident stats.