Yep, this is a deal-breaker for me, too.

Also, the Stellar folks should seriously consider the risk that much of their userbase can be instantly and permanently removed if Facebook is compelled to remove it by political or legal pressure — or decides they just don't want to be in thu business of providing authentication for currency schemes. (The same applies to tying to any other proprietary platform, of course; and Facebook may be less whimsical in this regard than, say, Apple.)