everybody talked about 51%,
but they don't consider why people would do this.
indeed, you ruin your self while you conduct a 51% attack.
Many trolls and scam-coins speculators would love to do this, but luckily they're not the ones with the ressources needed to pull it off

I'm sure a large part of the Scrypt hashpower is actually in the hand of Asic makers and farms who deal directly with them and have no interests in attacks.