Mate I aint got a single fucking clue what a DSLR is, but when you say

with a top end DSLR and a backpack full of lenses

I'm assuming hundreds of dollars minimum.

And I think if you really want a decent camera, it's gonna cost you some money, you don't just buy a shitty one over an ipad, if you actually cared about pictures you're gonna invest in that camera.

Just that using an iPad to take photos is stupid no matter where you are, wedding or otherwise.

No, that's stupid. It's a functioning damned camera, it it works, then it works. They may not have had a cellphone on them, or hell, the ipad camera could be better than their cellphone. Why does it matter to you if they use a camera you dislike?