I've drag racing for 56 yrs, and had never run an 1/8 mi until i moved from Phx. to Ms. in 1996. There's lot's of reasons for running an 1/8 mi. #1 the program moves faster,#2 less cool down time needed between rds. #3 less part breakage = less track downtime, #4 they usually have 1 or 2 buy backs, #5 less accidents, if a car is ill handling it usually shows that on top end of 1/4 mi. #6 as David says it more of a drivers race, since most races are won on the starting line and first 60', and if you can't get it done in 1/8 mi. you won't get it done in a 1/4 mi.
It goes back to 3 yrs. ago when NHRA, changed the fuel programs to 1,000 ft. a lot of people bitched, but they were breaking and wrecking in the 1/4 mi. some ran about 330 MPH in the 1/4 mi., some are now running 320's in the 1,000 ft, 320 ft less than a 1/4 mi. We have both 1/8 and 1/4, you have your option in T&T, but when the racing starts it's 1/8 mi.
In case some haven't noticed there are ProMods, running 215 MPH in the 3.70's, that plenty fast for a door slammer
JMO
Zip.