Psychology of the bad beat posts?

No matter which poker forum you read you will eventually come across a bad beat post. Sometimes the message is hidden as a question or in some other way disguised but the fact remains that a large number of people find it necessary to whine about their unfair beats.

I don't get it? It is a post about something that never has much relevance to others. There are no amazing bad beats in a single poker hand. The probability of a suck out never is that low and you will see it happen regularly.

The question is what motivates a bad beat poster? Sometimes the posters even excuse their post before they start to cry because they know that no one really cares.

I personally have never felt that I needed to communicate a beat, but admittedly I don't play for cash that matters so that might be a reason. However I am curious hear your opinion about it.