The thing is, there is such a thing as "low witchcraft". I haven't read Penczak's work, but in general I think the important thing here is to understand that "high" and "low" don't mean "superior" and "inferior". It's a distinction between two different approaches to magic, not a value judgement.
The high magic/low magic distinction isn't entirely on formality of ritual; it's closer to an academic/practical distinction, and it has the same class/gender issues to it.
The thing with the ceremonial stuff is that its practitioners describe it as being about enlightenment, purifying the soul, personal development, and so on: the sort of stuff one cares about if one has a lot of leisure time and doesn't have to do much work. It's this sort of thing that led me to coming across a blog a while back that argued that women don't do magic, because the smug jackass making the post was such a ceremonialist that ordinary-people-concerns just didn't register to him.
"Low magic", on the other hand, is oriented practically, to achieve material effects. Curses, blessings, fertility work, healing, protection. The sorts of things that your standard peasant farmer cares about.
Techniques tend to be more rarefied for high magic stuff, but that's a consequence of the class issues, I think, rather than the reason for the descriptor.
I think most magical systems have aspects of both (and stuff like "the protection one does so that one can do soul purification" probably falls under "high magic" in effect most of the time, even if protection magic is primarily a low magic concern). Especially systems in which religious stuff blends with magical stuff, they'll have both.