technically the answer is yes. projects can do sold out without bounty hunters. it may be an internal arragement within a specific group. imagine how bitcoin succeed without bounty hunters? it is purely the project fundamentals and perfect timing.
Yes, I agree with you. Instead of running bounty campaigns, they can promote their project by many ways. However, I think running bounty campaigns is much cheaper and safer. In case the ICO do not success, they don't need to pay anything. While bounty hunters can help to promote their project a lot.