If I "simply left" YouTube all my videos would be gone and nothing would change. Such extreme injustices caused by major web 2.0 websites can not go unchallenged.
Here's a "fun" fact: The american suicide rates have started going up since the early 2000s even though they had been on a steady decline up until that point. The reason is quite obvious: The rise of social media.
Pretty much every web 2.0 website has BS policies that work against their users' in some fashion (for wikia, it's that they give wiki owners free reign, which is a bad thing in many cases from what I've seen). Zippcast just happens to not be anywhere near as bad. They're completely transparent with their policies and will tell you exactly why they won't take action (they have a policy that says you can't be "willfully engaged" when someone is harassing you with a 90 day cooldown time) and actively protect their users videos from fraudulent copyright claims with no copyright robots of their own on the site and nothing that makes it easy for anyone else's copyright robots or fraudulent claims to harass you.