A lot of people without much programming experience seem to really struggle with nesting. We take it for granted, but I suppose it actually involves some reasoning about evaluation order of arguments.

For those people, persuading them to indent can be the difference between them having a chance of learning the knack or just flailing randomly, getting frustrated, and giving up.

(The other lesson is: if you're building a DSL for non-programmers, try to avoid putting in nesting and make everything really flat instead.)