I see this misconception from time to time, so here's a quote from why the lucky stiff on that very question:
I really only have two reasons for writing Shoes: (1) to act as the new runtime for Hackety Hack and (2) as an experimental programming platform for beginners. I don't think Shoes appeals at all to GUI programmers or to the marketplace. I don't even use the acronym GUI anywhere in Shoes docs or materials.
I want Shoes to get in the hands of hobbyists and kids!!
I think it's safe to say that Shoes is a toy - not in the dismissive programmer-slang sense, but in the literal sense that its primary design goal is to be fun. I think toy design is probably more important than people realize.