My experience with providers suggests that losing an erection, not achieving one, or not attaining orgasm is generally not a big deal for the provider.  This may be for any of several reasons, which can include a.) the fact that the provider is there first and foremost for the money; anything else —including sexual gratification— is secondary and may or may not be hoped for or even appreciated, b.) the fact that in the provider world, men are like public transit buses; there will generally be another one along in five minutes or so, or perhaps even c.) less clean-up is required.  

On the other hand, a sexual power outage is far more likely to be a big deal for the guy under the circumstances.  He's paid good money for the experience and —for reasons often beyond anyone's immediate control— is denied the so-called happy ending and possibly much of the pleasurable build-up to same.  At minimum, it's a disappointment —and no one enjoys disappointments, particularly when they've made a large investment in the occasion.

In the course of my life, as early as my early 20s, I have been subject to the occasional outage —both with providers and with women met socially— and one of the bitter ironies is that these seem to have occurred proportionally more often with highly attractive women.  The experience is by turns perplexing, embarrassing, aggravating, disappointing —and, above all, definitely not fun, no matter what the reason.  As if "a reason" can always be discerned.

With experience, one learns a little about other people's perspectives, one learns some attitude-adjustment tricks, one achieves additional personal insight and possibly some wider, deeper "perspective" of one's own.  And this is all very fine —and while every sexual encounter can be its own learning experience, it's not my understanding that we're there for the consolation prize.

This being the "over 60" forum [60 is the new 40?], I can say that the only benefit regarding these outages that may have come with a bit more age and experience is that —while I may not be any more accepting of them— I'm a little less profoundly troubled by them.  Emotionally numbness may replace humiliation, but, in my case, at least, neither is what I seek in a sexual encounter