The fact that the woman was breast pumping is pretty much irrelevant. This is a noise issue on a plane. You can replace 'pumping' with anything that makes noise: snoring, talking, eating, nail clipping.

The OP asks:

I'm just wondering if it woulda been ok to let her know the pumping was annoying? Have you met people? Strangers at that! You wanted to sleep right? What if you made noise when you slept...can someone wake you and ask you to stop? I'm sure you would have been able to tell her the pumping sound was annoying but I'm not sure you'd like her response.

As it turns out, I just stayed quiet and chose not to address the issue. Again, I didn't want to be the "insensitive DUDE" who doesn't value nursing mothers........ thoughts on this delicate issue? The issue is actually that you wanted to sleep but there was noise around you. Unfortunately you would have been the 'insensitive DUDE' had social media caught wind of the situation as it is wont to do. You wouldn't get any sleep and you'd be known as the guy who hates mothers. (For the record I don't think of you that way! )

If you fly often enough you could look into some handy headphones that block out most stuff around you and the next time someone is pumping (or snoring, talking or nail clipping) that will fade into the background as you fall deep into your slumber!

PS: Nail clipping is the worst!