The real mistake with Wave was that a group of incredibly smart engineers were basically allowed to go into a bubble and build whatever they wanted for an extended period of time. Successful innovation needs to be anchored by a real problem to solve. E.g. the best programming frameworks always come from someone who is building a real app on top, not from someone who set out to build a programming framework. The feedback loop is necessary to keep developers focused on the actual needs of users, rather than on whatever problem they find most interesting to solve.
I think Eric is referencing the poor usage numbers as a proxy for the fact that the Wave team was not building something that users really wanted.
(FWIW my own startup, Sandstorm.io, had a pretty poor record on this point as well.)
The Larry approach sounds more vision-led and its interesting how it looks when it fails. Its difficult to see beyond the survivorship bias and only see it as egotistical and ignorant failure.