These are just unnecessary. You don't have to stop coming to the site if you want to focus on real life stuff. I mean, by all means leave if you want to, but you never know if you'll ever want to check up on the site with the occasional post or something (or just to lurk). A website is not a commitment, (unless you have greater ties to it) so if you want to go, just go, because you're not obligated to state yourself leaving and if you do want to come back you'll just seem silly to everyone.

Look at Ayreon, he hasn't posted in forever but he never said anything about it. But different strokes different folks I guess.