Much of the family lives in rural locations and is nice to charge while visiting. Many have welders (6-50), most have dryers (14-30 and 10-30), some have air compressors (6-20). Add in the 14-50, 5-15 and J1772 like you said. Now I'm prepared to visit family.
By my thinking, the 5-15 is pretty close to worthless since it charges at 3MPH: 120VAC charging is a joke. So I was trying to get every possible 220V there is, hoping that I could find one somewhere nearby in a pinch.
But, to your point, have not used them all yet. But I haven't visited all the family yet either. At $35 a pop, is cheap insurance to just throw them in the frunk.
Hmmm - after reading this post - I guess I must have a case of 'plug anxiety'. Beats 'range anxiety'...