Which functional language are you talking about? Of the two functional languages I know, Elm can only have a single return statement. Scala encourages a single return.
To make an example the following expression can be considered to have two returns:
max x y =
if x > y
then x
else y
int max(int x,int y) {
if (x>y)
return x;
else
return y;
}
int max(int x, int y) {
int result;
if (x>y)
result = x;
else
result = y;
return result;
}
int max(int x,int y) {
if (x>y)
return x;
else
return y;
}
In imperative programming, a bunch of nested conditionals can easily have incomplete coverage of possible program states, and it can be easy to overlook problems if you have a mixture of side-effect branches and early returns. I think some people struggle with this more than others, and it can flummox them almost like goto-laden spaghetti code.
Of course, there are other areas where similar errors can occur in different languages, i.e. in exception-handling or pattern-matching constructs. There are many different coding styles which can make these control-flow structures easier or harder to debug. But, I think there can also be a lot of "cargo culting" where zombie rules of thumb continue beyond when they were really particularly helpful.
The fact everything is context-dependent is the basis of all these discussions to begin with. We severely lack evidence and most rules are hearsay taken as gospel.