> - As a business I will link to a youtube video but not a PT video because I know YT will stay up.

So you never stumbled upon a news or blog post (or playlist) containing an embedded video thats now "no longer available due to copyright issues", "switched to private", "not available for your country", "deleted by the user", ...?

Happens about once a week to me. Thats why I started to "backup" my playlists with youtube-dl.