This is not a new phenomenon though. Look at tech bubble #1. hell, go back in time and look at Tulip Mania or the railroad bubble in the late 19th century.
Wall Street will continue to do what is in it's interest. With average returns from Underwriting an IPO in the range of 7-9% they have to.
Wall Street doesn't care that mum and pop investors get screwed - they just need to know that there are more out there that will continue to buy IPOs if they are presented in the right way.
BTW, IPOs have been in long term decline (in terms of absolute numbers) for ~20 years now - see the economist