Not surprising to me at all. I am a big fan of early U2 right up to "Joshua Tree", after that not so much.
For me they are a beneficiary of timing as much as anything else, there is simply no other rock band that can rival them during the last two decades, the only two I can think of are ZZ Top, and Rush and ZZ Top has not been busy enough to be relevant. I like both bands more than U2.
I do wonder if Bono had not been stricken with delusions of grandeur and become political if U2 would not get as much stick as they do these days.