I am just a normal user of the site. I use it rarely as a training of my coding skills, so no offence taken.

Well, if insertion and deletion are also involved in the edit distance, a simple XOR cannot solve the problem. The graph solution to RNAS would be terribly slow (not only in Perl) and one would run out of time (there is a 5 minutes limit). You have to find a way how to solve the problem without going into representing the graphs at all. That was what took me some time, once I knew the algorithm, the implementation was a routine.

It is true that most of the simpler problems can be solved by one-liners in Perl. The site does not care about how you solve the problems: you just download the test data and have 5 minutes to upload the solution. That gives us Perlers an easier start on the ladder.

I agree with you that the jargon used by some bioinformaticians is incomprehensible. I fear the reason sometimes is they do not understand the underlying problems in proper detail, it is just a form of handwaving.