More than likely it's a cost savings, not a performance thing.
Look at the entire Toyota line up and tell me how many true performance vehicles you see. How about ZERO. Even the Lexus sports car is overweight and underpowered for its class. It's truly a sad day for the company that brought us the AE86 Corolla, the AW11 MR2, the ST185 All-Trac Celica, the JZA80 Supra, the SW20 MR2, and even the MRS. The only hope left for a true performance vehicle is the spy shots of the LF-A, and few people will be able to afford that car. At least Mazda, Subaru, and Mitusbishi are addressing the sportscar enthusiasts with real performance cars. Sad day. I'm never selling my Supra.