The new excuse is that even if there is a bubble it will be contained. It does seem an entire bubble economy has been created in SV where bogus companies provide bogus products and services for other bogus companies. Maybe in this case any collapse would be contained, but I guess we'll have to wait and see.
As the expression goes: Anything that can't go on will stop.
My guess is it continues. Hedge funds as a whole also perform below market but see continued investment because of the promise that they will have tremendous returns when a firm succeeds. Startups get money from the same sort of investors. People who are only investing a portion of their portfolio, chasing big returns and mostly unconcerned about losing some money along the way.
Let's take a reasonable definition of a bubble: when the price of an asset has risen much higher than what is justified by the market. By that definition I don't think we're in a bubble, I believe investors are logical and they know they are taking risks chasing a large return. I also believe investors will continue to chase big returns from tech companies and that there is precedent for this behavior in other types of investments.
The new paradigm is far more interesting, since it's almost all the investment comes from VC and Angel Investors. I think these entities can leverage risk far better, since they may lose a few million here and there, but when they hit a whale they really hit big.
I think there might be 'micro bubbles' within the industry that may implode under their own weight (F2P mobile games companies come to mind), but I think that's largely separating the wheat from the chaff.
I know some will disagree with me on this analysis, but I don't really subscribe to the sky is falling theory. The tech industry is now big business, that's not going to change.
Stock bubble? Economic stability and the wonderful controls the Fed has on monetary policy. No more economic cycles.
First tech bubble? The internet is a wonderful thing we haven't had before - new opportunities, etc.
Everything is different until it isn't.