Come to think of it, given how most websites are designed, I'm starting to think we're making a mistake with sticking to HTML/CSS/JS. We should move to "executable Photoshop image" format - so that the beautiful magazine-like layouts made by designers could be implemented without a shit ton of hackery and bloat webdevs have to put nowadays. We could also push some security and sanity decisions into the format this way, so that the tool itself would tell the designers they can't (or shouldn't) do something.
(I'm only slightly sarcastic here.)
Call them boss, call them stakeholder, call them prospects, call them whatever you want, point is, progressive enhancement requires actual hard work, it's not the default state of things when you move beyond the "research paper" format of having a bunch of paragraphs of text interspersed with section titles on a completely static page.
PE is not what the client pays you for.
> You have to go out of your way to screw it up.
Hardly. The shortest path to the whizzbang the client wants will break PE all on its own.