I figure that freezing the top row is an additional step that, unless you know how the sort works in the first place, obscures what's going on.

I like that Google does it that way. I still don't recommend their spreadsheets to people because, especially if you're dealing with a non-web-savvy audience, figuring out how to access a Google spreadsheet and "cloud computing" more generally is more confusing than just emailing someone a file. And if you're going to email someone a Google spreadsheet, then you're probably going to export it as Excel. Et cetera.

I think of Excel as a ladder that most people have to climb in order to kick away.