> Sabbaticals are reserved for tenured professors
Why do you think so? Sabbatical means a break. It's common for professors, but why prevent other people from taking it? I took a sabbatical from my uni to do some real work (and ended up moving unis, countries as a result), then took a sabbatical from work for personal reasons and did other things I wanted to do.
If that prevents a burn out for someone, great! Not every company has enough projects going on to reshuffle you to the place you enjoy. (Or may not want to for valid reasons) Not every sabbatical is about burnout either.