On the other hand, I think there are several "unicorns" that are still private that will do well as public companies -- Dropbox, Lyft, Stripe, and Airbnb. The success of these in the public markets will help the startup ecosystem and encourage venture capital funding.
With that said, I find the case of Blue Apron interesting. I have a hunch that it may have thought its best chance to go public and cash in was now -- that the environment for "unicorns" like itself (one that faces substantial competition, a weak product, fickle customer behavior, lack of customer retention and unstable cash flow) will only get worse.