The media producers care about the new release window, where they capture a disproportionate share of the revenue for each title. The new release window is measured in days, not weeks. If DRM spares 50% of the new release window from readily-available high-fidelity copies, they've potentially saved significant revenue.

All this boils down to a simple point: the goal of DRM isn't to protect titles from being copied. It's to make copies more expensive, which in turn makes it take longer for copies to spread.