Earlier quoted context omitted.
How exactly would they inherit the genes if it causes sterility?
Sterility is just one example of gene modification. A harmful modification that doesn't cause sterility will propagate across generations if the indivuals are able to reproduce. For example a scenario where we see the symptoms but we don't know that they are caused by a gene modification. And where individuals are still able to live and have children. And I'm not saying that the tech is bad. I'm sure that people can…
If it's harmful, it will get selected against, and will disappear rather rapidly.
There's a reason why they need to release 750 million genetically modified mosquitos, and not just 1.