This document is an application, not a patent. It may or may not get issued as a patent. As George White explains, the invention itself is not unethical. As a device, it could be useful to any manner of consumers who need a little extra help riding their bike.
I absolutely do agree that if the inventor or company owning the invention intentionally sells such a technology to bike racers with the intention of getting an unfair advantage then that activity is unethical. It is even possible this activity might be illegal although I'm not a lawyer. The publication of the application, if anything, helps bike racing authorities be aware of the potential for "mechanical doping" and may help them develop ways of detecting it. As for "LA", he stopped racing in 2012, long before this application was submitted so I'm skeptical he ever used a motor assisted bike. The question there was more about conventional doping.
This is essentially the same as the development of medications such as steroids which have a useful therapeutic value but can be used off-label for unfair and unethical advantage. The fact that the drug was developed and patented isn't the problem, it is how the drug is used that matters.
Interestingly, I'm not even sure this patent application is novel. The priority date for this application is 12-26-2016. This article published 2/1/2016 and shows a picture of much the same technology. Here is a different company that sells pretty much the same thing.