I've never seen a company do that, though.
It's still a garish design anti-pattern, nonetheless. All this baroque excess of late with gigantic fonts in the name of "space" and "readability" really needs to stop.
I used http://lamb.cc/typograph/ with a "Le Corbusier" scale to calculate the font size, the paddings and margins etc.
So the size does not come out nowhere, it has been made for readability and as my eyesight decreased, I found the change much welcome… I will try to find a good balance to end up your sufferings ;-)
The discussion in [1] on "vertical tempo" is interesting because I think that is precisely the problem with your site. Your body font size is large but within currently fashionable standards [2] at around 10 words or 60 characters per line; but the headings and subheadings are so huge they are breaking the vertical flow of the page.
On my iPad, for instance, it currently takes me an unreasonably long 27 (!) full screens to scroll down to the end of the article, not counting the header (another full screen) nor the comments section. And often the subheading alone occupies the entire screen. With such huge disparity between body and headings size, it makes little difference whether both sizes come from the same proportional scale or not: the sheer size difference is perceived as out of proportion nonetheless.