TRD has mostly very high quality (OEM level fit and finish) parts, that are on the conservative side.
There is definitely a market for these types of parts! Not everyone wants the fastest setup out there, made by a small speed shop. Some want parts developed and produced with the backing of a major company with no impact on warranty or emissions legality.
While this has been the recent norm for TRD, you may want to take a look at their history in a bit more detail. Like the development around the NA Beams 3SGE.. 2.0L 270+ hp NA 9,000 rpm.
Look at the cams, the awesome exhaust manifold and ITBs.
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http://trdparts.jp/english/parts_engine-3s-ge.html
We can hope TRD is getting more serious with the recent offerings for the Lexus IS and the launch of the BRZ/FRS/86.