Genetic engineering has the same effect as selective breeding, only greatly accelerated. I don't have any problem with using it to repair deleted genes in people. Many serious diseases are caused by deleted or miscopied genes.

I have trouble with transgenics ( grafting genes from one species to another) in higher animals and flowering plants. These could have unforseen effects (corn that kills monarch butterflies, for example.)

I think genengineering of bacteria to produce insulin, vaccines, etc. is a good thing; the organisms must be controlled.

Organisms designed to eat toxic waste are interesting, but again must be constrained from entering the general environment.

Genetic engineering in humans to enhance a desired trait is eugenics and as such objectionable.

JMHO.