As I've gotten older, and my penile sensitivity is naturally dropping
, getting off through a BJ is increasingly difficult. We're all different, and some guys never respond to a BJ.
But the thought that a guy has his mouth around my dick is also exciting, regardless of what I'm physically feeling. And frankly, some guys are BJ artists, and some are rank amateurs. My dick in one guy's mouth is not the same as in another.
A few years ago I stayed a weekend with a guy who had a fantastic oral technique. Not only did he get me off in his mouth, he got me off while we were 69ing, something I had never done before, nor since (I also got him off at the exact same moment, too, for a mutual climax that was spectacular).
I honestly have never found a man I couldn't blow to a shattering climax. I think the problem in most cases is the mouth, not the dick. But some guys are the exception, and won't get off that way, no matter what. That's OK, consider it foreplay, enjoy it for that, and do what finally works for you. It's all good.