Agree with all the comments, but I think we need to define rockstar. To me a rockstar is someone who wields influence and a reputation for getting stuff done ... not necessarily someone who has wicked skills or actually was the one who got stuff done. Those are the people you are being warned about. Instead get those with wicked skills (which some people call rockstars).
That said, there is a place for rockstars (the influencers, not the doers) in some ventures. For example if your target customer is at the enterprise level, or something decided by another influencer (like a CEO, or board of directors) then you're going to need some clout, and it's helpful to have some strategic influence right out of the gate.
If however your target customer is the consumer, or maybe an IT manager then staffing your startup with such rockstars merely constitutes costly wasted window dressing.
If you do bring on rockstars because it fits your need, then as others said: be careful of the "too many chefs, not enough cooks" scenario. If you're paying them what such rockstars expect, then expect from them commensurate results (even if it is merely from influencing deals, which can be invaluable). When used, they're good for filling spots on an advisory board or as a board member with no specific title other than "Finance" for example. There are rockstars who are worth their egos and pay ... but few startups have the resources for them.