I own bitcoin because like kleenex is to tissue, or clorox to bleach, so bitcoin still is to crypto.

If bitcoin drops by half, then they fix, it will rise. If they adopt some hash graph like technology, all their current problems are over (no segwit or lightening req'd) and they will again dominate the market. I say buy at $8500 because I believe the NYA group still can and will do the right thing.

tl;dr: Because branding.