You can compare the velocities for yourself on Jeff's review linked above. If we are comparing 9mm to a .357 revolver, the 9mm rifle can do good work. True, .357 Magnum out of a rifle will open up the gap again but I think the comparison was that people seem to think that a .357 Magnum revolver is "powerful enough for deer hunting."
The big advantage of the larger .357 Magnum case is going to be heavier bullets/slower powders. Quite obviously 9mm is never going to be able to match the kinds of hunting loads we see using 158 grain and 180 grain bullets. But if you are talking about 115-125 grain Gold Dot or other bonded bullets which should stay together at higher velocities... should have potential.
And I have to agree, any carbine is going to give you far greater hit potential under stress. Especially over any kind of range at all. Multiple attackers spread out over 25-50 meters... really... would there be any doubt you would be better off with a carbine than a handgun for both hit potential and time between shots?
re: Ruger .44 carbines
I've got the later model, the one with the detachable magazine. It's a great little rifle. I normally hunt out of a tree stand and the deer are never further than 75 meters away. And sometimes I get bored and start trying to move slowly through the thick stuff, trying to get one to jump up practically under my feet. That's almost like quail hunting. For both types of shooting, the Ruger is just about all you need. I'm always taking "something new" out to deer hunt but honestly I could just use that little rifle every time and it could do everything I need. The accuracy is more than enough, it cycles perfectly, recoil is nearly non-existent, a second shot is quick (although I've never used one) and .44 Magnum out of a rifle is deadly. Put a short light scope on it and it can do the job.
If you take my .44 Magnum carbine and put it side by side on the bed with my Ruger 10/22, they are virtual twins. A sharp eye would notice the thicker barrel or the plastic operating rod guard but they are virtually the EXACT same size and profile. Think of how quick and easy the 10/22 swings in your hands. The .44 is the same thing.