In this essay I argue the following:
Brain emulation requires enormous computing power; enormous computing power requires further progression of Moore’s law; further Moore’s law relies on large-scale production of cheap processors in ever more-advanced chip fabs; cutting-edge chip fabs are both expensive and vulnerable to state actors (but not non-state actors such as terrorists). Therefore: the advent of brain emulation can be delayed by global regulation of chip fabs.
Full essay: http://www.gwern.net/Slowing%20Moore%27s%20Law
That seems as though it is basically my argument. Biomimetic approaches are challenging and lag behind engineering-based ones by many decades.
I don't think WBE is infeasible - but I do think there's evidence that it will take longer. We already have pretty sophisticated engineered machine intelligence - while we can't yet create a WBE of a flatworm. Engineered machine intelligence is widely used in industry; WBE does nothing and doesn't work. Engineered machine intelligence is in the lead, and it is much better funded.
If one is simpler than the other, absolute timescales matter little - but IMO, we do have some idea about timescales.
Polls of "expert" opinions on when we will develop a technology are not predictors when we will actually develop them. Their opinions could all be skewed in the same direction by missing the same piece of vital information.
For example, they could all be unaware of a particular hurdle that will be difficult to solve, or of an upcoming discovery that makes it possible to bypass problems they assumed to be difficult.