re: Why does restaurants always have Heinz ketchup in glass bottles?

Oh, and the answer to the OP, at least as explained by my old boss:

You have to cut costs anywhere you can. With an easy squirt bottle, people put WAY more ketchup on their plate than necessary. As a server, I threw out more side plates full of ketchup than I can even begin to count.

With glass, you have to work harder to get the ketchup. It keeps people from squirting half the bottle on their plate.