That has not been my experience. I spent years working on DNA aligners then in a wetlab building software for confocal laser microscopy. In both locations, the best paid and most highly valued people were the scientists. If you, say, were a good developer with masters in stats and a strong understanding (somewhere between an undergrad and an MS) of the relevant science... you were paid 1/2 as much as you would be paid if you did computational advertising.
And yet there aren't many good developers doing science. Weird, huh?
Agreed that low salaries are a disincentive for good engineers to work in science. It's worth noting that even the scientists are paid far less than people with commensurate training and experience in industry.
As for why scientists are more highly valued: they bring in the grants that keep the wheels turning (in academic circles; industry & national labs obviously differ).
That's possible. I have a friend who works in the university aerospace lab that can read and write C and Matlab. His major contribution is being able to both understand the engineering and write code to manipulate it, and it's basically guaranteed himself a position there. He may not be valued quite as much as the PI or one of the other professors, but he's pretty solid.
I'd also cite myself, but I don't count since I'm in a robotics lab.
Sequence analysis companies and labs which don't value software engineering get what they pay for: serious or crippling inefficiencies and inability to do analysis on their data or maintain continuity. Unfortunately, many of them don't even realize what they need or how bad their inefficiencies are.
And yet there aren't many good developers doing science. Weird, huh?