Please show us evidence of your unlocked fps Evo running higher than 30 fps in a 3D benchmark test. I can OC mine to 1267, run my Gumbo hack on the RAM, and install a Froyo build to get a Linpack of over 40. Still can't get 30 fps in Neocore. And Neocore is designed specifically for Qualcomm chips. Scores on nenamark are still pitiful.
Because the GPU is not capable. It's not on the Dinc, or the Desire, or the Nexus One either. The Evo just was not designed to be a 3D powerhouse, and likely no HTC phone ever will be.
Does it piss me off that HTC took it upon themselves to decide between HD out and framerate? Yeah, a little. It used to irk the hell out of me. But after undoing their work, and seeing the result, it's a non-issue that people are going to cling to because they feel cheated.
BUT -- all hope isn't lost. It looks like the Snapdragon/Adreno GPU clock speed can be almost doubled, which WILL improve performance (See Acer Liquid)