"Profitable, high flying startups like Facebook and Zynga don't bother going public anymore."

Um, Facebook and Zygna aren't startups anymore. Startup != privately-held company.

Yup. The only thing that's new in this is the private money that's coming in before the IPO. The founders and early investors can get a big chunk of the IPO value right now without any headaches, and the new money cashes in on the expected IPO down the road. There's really not much to see here.