google is not going to penalize websites just because of their domain name. but if you have a retardedly hyphenated domain name, tons of low-quality links that popped up overnight, spammy on-page optimization... well, you kind of just spelled it out to them that you're a spammer.
having a legitimate site with a dash or even two in the domain by itself isn't going to hurt you in the SE's. but it's not the greatest branding idea either.