Yes, I agree. An electric winch is not just going to drain a battery instantly. I have seen an electric winch without the engine running either pull a stuck vehicle out of a hole or back on it's wheels many times with plenty of juice left in the battery afterwards to restart the engine.
Sure, you can't pull for really long distances with an electric winch without the engine running, but most stucks or rollovers only require maybe 10 feet of pull.
The only advantage for a hydraulic winch I have personally witnessed was on a ride last winter. The trails were very wet and we had several fairly stock vehicles with us that could not make it up about a 300 ft. hill. One guy in our club with a hydraulic winch pulled 3 or 4 vehicles up in a row. I'm sure an electric could have done the job, but may have required more breaks to recharge the battery and cool down.