Why recursion is so important

I was just writing a little program that should generate all possible combination out of a list of chars. In my brain something like this evolved:

 1: wl = ['a','b', 'c', 'd', 'e', 'f', '']
 2: out = []
 3: 
 4: for i1 in set(wl):
 5:     for i2 in set(wl):
 6:         for i3 in set(wl):
 7:             for i4 in set(wl):
 8:                 for i5 in set(wl):
 9:                     for i6 in set(wl):
10:                         for i7 in set(wl):
11:                             types = i1+i2+i3+i4+i5+i6+i7
12:                             out.append(types)

But I think everyone can see that that was a stupid idea.
Saying that I have seen that in quite some projects. My next thought was to bring recursion into this.

 1: wl = ['a','b', 'c', 'd', 'e', 'f', ' ']
 2: out = []
 3: 
 4: def recLoop(txt):
 5:     if len(txt) >= len(wl):
 6:         out.append(txt.replace(' ',''))
 7:     else:
 8:         for i in set(wl):
 9:             recLoop(txt + i)

This looks far nicer doesn't it. I hope everyone who programs can see this. Just to state how important recursion is and I don't really understand why unis don't teach this more.