You're questioning the fundamental philosophy ow Wall Street (I almost wrote capitalism instead but I don't know if that's true). Solvency is not enough to drive stock prices because the price of a stock is a bet on the future value of the company, not the present value. I don't like it either...
It's not really about "like" or "not like" but fundamental economics and mathematics: things that grow behave differently then things that don't, and are worth more. Suppose FB found a way to consistently make 1B a year, give it to the investors, and only grow as much as inflation. Then the valuation would settle on something like 10-15 billion (plus however much cash it has on hand at that time). And a solid part of the market will love it as a long-term investment and tout its value. On the other hand, to value it at 50 billion you have to assume that its earnings will at least quintuple over time, so good luck to them.
You can't call this a Wall Street philosophy; Facebook was trying to grow massively before they were public. In fact, that's where the growth was happening. At any point in time they could have decided to remain where they were, with the money they were making to pay the bills, and stayed private. They didn't. Instead, Facebook told us that they were going to, essentially, grow the company to 5 or 6 times the current state.
In other words, Facebook caused Facebook's problems, not Wall Street.
But the most important factor that is considered during the IPO dog and pony show is projected growth. Nascent companies need at least double digit growth, preferably triple digit. And every quarter, when public companies announce their earnings, year-over-year, the stock price is impacted as much by revenue growth as it is by earnings/share. Ignoring high-frequency trades, the two main philosophies of trading on public exchanges are value investing (Warren Buffet) and growth investing. Facebook caused Facebook's problems in hopes of maximizing its IPO.
Edit:fixing phone-induced typos.