Computers mostly are
* well understood at every step (well, at least it was all designed by humans and the bits and bobs do what they say on the tin).
* mostly involve producing some kind of output for everyday normal people to use, in the end.
So they are easy to understand and evaluate. Even some investors can manage it.
Biotech stuff seems to mostly involve making tools for other technicians and scientists. And the process by which is works is some ridiculous, quirk-laden byzantine madness that evolution happened to throw together. At least from an outsider point of view it seems like an absolute nightmare.