I'm going to tell myself it's because they bought the trades, and didn't want both editions taking up space.
I wish I could find good back issues around here; as it is, I'm lucky if I can get anything older than about 5-10 years. :/
(It wasn't that way when I started collecting. There were two stores which had huge runs of back issues; one closed down, the other went through behind-the-scenes changes.)
~ Le Messor
"Money is the root of all wealth."