How Safe are Uploads?

I have encountered the argument that safe brain uploads are as hard as friendly AI. In particular, this is offered as justification for focusing on the development of FAI rather than spending energy trying to make sure WBE (or an alternative based on stronger understanding of the brain) comes first. I don’t yet understand/​believe these arguments.

I have not seen a careful discussion of these issues anywhere, although I suspect plenty have occurred. My question is: why would I support the SIAI instead of directing my money towards the technology needed to better understand and emulate the human brain?

Suppose human society has some hope of designing FAI. Then I strongly suspect that a community of uploads have at least as good a chance of designing FAI. If I can find humans who are properly motivated, then I can produce uploads who are also motivated to work on the design of FAI. Moreover, if emulated brains eventually outproduce us signfiicantly, then they have a higher chance of designing an FAI before something else kills them. The main remaining question is how safe an upload would be, and how well an upload-initiated singularity is likely to proceed.

There are three factors suggesting the safety of an upload-initiated singularity. First, uploads always run as fast as the available computing substrate. It is less likely for an upload to accidentally stumble upon (rather than design) AI, because computers never get subjectively faster. Second, there is hope of controlling the nature of uploads; if rational, intelligent uploads can be responsible for most upload output, then we should expect the probability of a friendly singularity to be correspondingly higher.

The main factor contributing to the risk of an upload-initiated singularity is that uploads already have access to uploads. It is possible that uploads will self-modify unsafely, and that this may be (even relatively) easier than for existing humans to develop AI. Is this the crux of the argument against uploads? If so, could someone who has thought through the argument please spell it out in much more detail, or point me to such a spelling out?