1. You're never in the awkward position of being the first to arrive.
2. Because you are honest enough to admit that NO PARTY EVER STARTS WHEN IT SAYS IT WILL.
3. THEREFORE, in many cases you are actually doing the more polite thing.
4. And if a party runs out of beer or snacks, you can easily pick some up your way (and then get first dibs).
5. Being late lets you receive a warning in time to avoid a cringe-inducing situation.
6. One the one hand, you can seem very busy and important...
This Facebook poke war won't just conduct itself, you know.