I would say iOS development is more front-loaded in the amount of things you have to learn before you can build even a simple app than it is for web development. The net amount of work might be less in the end (as you say, there are a ton of technologies to learn in web dev work), but you don't have to learn all of those at once if you want a webpage.
Totally agree with this. Once you get past a certain point the intrinsic complexity of the problem dominates, but the initial learning curve on Obj-C and Cocoa is definitely steeper. You can't just slap something together the way you can with PHP, for instance.
And I believe that was the point he was making.