That's a completely different argument. "Researchers think we'll get two more orders of magnitude in a reasonable time" is quite different from saying "if we extrapolate this curve, we'll get there in 5 years". After all, exponents describe growth until they don't-- eventually we reach physical or economic limits (Moore's law has tapered off; bacteria in a dish of agar show exponential growth until they don't anymore, etc.)

I highly doubt we'll get there in 5 years, myself.