I found SNOBOL a lot harder to work with than Icon. Icon is an Algol-like language in that it has the usual flow control mechanisms, enhanced with Icon's backtracking. SNOBOL is a lot more like assembly. So it's harder (for me) to read the basic control flow of a program.

I think SNOBOL predated the invention of structured programming, or at least Griswold wasn't aware of structured programming's advantages when he designed it.