I think they did want it, but it was a mix of cost, development challenges and value. The Wii U gamepad has zero latency - it's actually quicker than the interaction on the TV. This has marveled a lot of tech people who analyzed the system. Getting that up and running on PS4 probably would have been a challenge in the time frame between when they saw it displayed for Wii U and when they wanted to ship PS4. Cost is obviously huge since they knew they couldn't do a $600 system again. And really, every Playstation has essentially been a more powerful version of the one before and the market likes that, so is there really a value in a touch screen for Sony?
Personally I would have enjoyed if Sony (or Nintendo) made a system a little weaker than PS4 and with a small touch screen on a Wii U Pro controller type interface as a standard controller for all players on the system. Would have been cool if sold between $300 and $400.
Also, I think Sony really should have thought harder about the thumb stick position. The low placement is not ergonomic, no matter how used to it PS gamers are.
