Ever play any of the ol' DOS X-Wing series? Transports abounded there. Made lovely explosions with the port or starboard little fins coming off and doing a barrel roll before blowing up.
DSTs are like that, old school
Yeah, go to 3:55 in this video. http://www.youtube.com/watch?v=VWghOA692w0
A few transports getting blown up, and then a minute later attacking some Bulk Freighters. (p.s. that pilot is terrible....)
The game came out in 1993 and as far as I know it was the first time Transports were used. Back in that game though they weren't called Stormtrooper Transports, they were just Transports, or TRN. Later on they took that name, so to me at least it makes sense that they AREN'T called Stormtrooper transports here