I would say this probably varies by person. I learned a lot by using multiple distros. When I put the dots together that yum, apt-get, and (later) pacman do the same thing, that was a huge ah-ha. Sometimes seeing the differences in how they work in command line especially helps you understand larger concepts. If you stick with one distro (like I did for too long) you may have trouble comprehending these concepts for longer. Some beginners may find choice overwhelming, yes, but I do think it can be useful having exposure to two or three distros out the gate…even if just on live USB.