That said, a public company that has an incomplete product roadmap-- or poduct, shows no profit and has a poorly understood revenue strategy is immature. GM has been public for a comparable amount of time. It is well understood what they do-- they make and sell cars. Twitter aggregates and dynamically prices advertising and monetizes information. It is much harder to understand a new business model and one that is not making money. It was not ready to IPO.
Yes, the market goes up and down. Twitter was a shitty company, still is a shitty company and will be a shitty acquisition. I understood that and I didn't buy it. Thats how the market works.
Edit: While the market goes up and down, Twitter has pretty much just gone down. It was in the 50s 2 years ago and has pretty much just fallen.