I have flagged quite a few posts and answers, 2 of which were spam flags and both were declined. Why? Isn't spam anything redundant and lengthy? For instance, if a person's answer is "hieeeeeeeeeeeeeeefiehfihfiehihefhehfie" some random letters like this, is this spam?
That is not spam.
On StackExchange, only posts that explicity advertise a specific website, program or product are considered spam. Gibberish should be flagged as either "not an answer" or "rude or abusive".