I remember going over some html I had written in person with one of those coworkers. I had forgotten to write alt text for an image, and the filename itself was some ugly hex string or something. When he got to that part of the page the screen reader starting reading off the filename - it sounded like it was speaking tongues! His nose scrunched up and he shook his head disapprovingly: no, no no! After hearing that cacophony myself, I now try to remember to make things as accessible as possible.