GMO Skepticism

I'm all for GMO, but there is room for concern. Aside from Neil deGrasse Tysons's expertise, his argument was too simple: everything we eat is a GMO to improve yield so that more people can eat,  therefore all GMOs are good.  What if that an organism was genetically modified to bind with pesticides more effectively? Yield would improve, but maybe at the cost of humans consuming more pesticide, creating some problems over the long term.   This is just a hypothetical situation.