If you remove the questionable assumption that most of the ideas are good, isn't it rather kind of institutionalizing "throw enough shit at the wall and some of it will stick?"
Yes, but you say that as if it was a bad thing. For me it was a really hard experience when doing science, that I could not "be smart about it", and do things "in smart ways", because that would require me to be able to predict which experiments would work out etc. Any high uncertainty environments are "throwing shit on the wall". You can't be smart about the throwing part, only what you do when something sticks. This is very hard for smart people to accept. See also: http://www.ted.com/talks/uri_alon_why_truly_innovative_scien...
Sort of. It's kind of institutionalizing the process by which you acquire and throw shit. And this is what should be institutionalized if you agree with Scott's premise that "success in the start-up realm is mostly luck".
I think it's always been like that, it's just that the internet allows light-speed iteration, hence you see the same phenomenon that would take decades in the past happening within days.
The difference is the analytics. If it's a good startup it's going to learn so much from the shit on the wall that the next pivot will be much more informed and likely to be succesful.