Hydraulic power costs weight and money though.
Figure a 17gpm system, you would need at least a 10-12 gallon hydraulic tank ($300ish), hydraulic lines (minimum 0.75" pressure and 1.5" suction lines, figure $500-1000 to start with), 2+ solenoid valves ($1000ish?), a hydraulic cooler somewhere with a fan on it ($300ish), a pump on the engine in the serpentine belt path ($750ish), cylinder(s) ($100-300 each), at least one hydraulic winch ($2800), etc AND space to mount it and make it look like a "clean" install.
By the time you put all that together they would probably be pushing $6-8k (I got $6k with 1 winch and 1 cylinder on solenoid valves), not counting their time to set it up and make sure it worked properly and they didn't have undersized lines, too many elbows or other restrictions in the flow path (and most of that time would be "boring" and not interesting enough to put on their channel).
If they don't currently need hydraulic winches to do recoveries the way that they do, why would they change things for this one truck versus having everything work pretty much the same on all of their vehicles?
Running a couple heavy cables for power and heavy alternator (or two) is a lot easier and cheaper.
Aaron Z