I think some would say so but it isn't true in my experience. We have 18 or 19 mules that I work with every summer and a couple more in the fall.
For a greenhorn I'd look at spending a bunch of money on an old mule that has been there and done that. We get cheap mules quite a bit but they usually have issues. Hard to catch, hard to load, kicking, not leading, bucking, you name it. After lots of miles of packing they mostly turn into pretty decent pack mules. But the average guy isn't going to have that chance. Spending a bunch now will save you money, blood, and sweat later on. Trust me. And the same is pretty much true for horses although you could probably get a decent pack horse for less than a good mule.
Also most any mule or horse will do much better with a buddy around.
