Well that has been their ethic since HL1,
"Add technology for a purpose, Not for sake of having it."
Edit:
Here is the exact quote,
Yahn Bernier wrote:There were a few important things, the most important, in my opinion, came down to building the right team. Other significant decisions included knowing what we wanted the products (HL2, CS:S, DoD, etc.) to be rather than just building up technology for the sake of technology. Other than that, allowing sufficient time for the good ideas to percolate throughout the game and the bad/unimportant ideas to fall away.