Because ouch. Now flats hurt as well.
I once tried on a pair of those really high heel Steve Madden shoes on a lark, and it's a miracle I didn't fall over and crack my head in those.
Either way, I am certainly not judging as you know. I've gotten the OK to wear my comfy shoes to the Capitol, even when I am more dressy (ie committee hearings or meetings with a legislator instead of staff). Thank you, employer. And if that is what you need, I hope your employer can be as flexible. I figured it was OK when I saw our Director wearing sneakers with her suit.