This is one reason on why we tread cautiously. I'm sure others can provide more examples

https://en.wikipedia.org/wiki/Raoultella_planticola

"In the early 1990s a biotech company set out to solve a problem: how to destroy crop residue safely. Some crops' residues harbor plant pathogens. Burning is occasionally used to destroy the residue and pathogens, but this is a fire hazard and can be dangerous for the environment. This company realized that, because R. planticola is an aggressive and abundant soil bacterium, it could be genetically modified to destroy crop residue and also create ethanol. Testing of this process, however, was limited to sterile soil. Ph.D. research conducted at Oregon State University, supervised by Elaine Ingham, obtained a sample of the genetically modified organism for assessing ecological effects through the German Institut für Biotechnologie and, testing it in non-sterile (ordinary) soil, found that the modified bacteria caused mass plant death from the ethanol production. R. planticola is ubiquitous, found growing in the root systems of all kinds of plants everywhere. Therefore, some have speculated that without the independent test, the genetically modified bacteria might have been introduced in nature and then could have spread to contaminate the biosphere where it would cause worldwide plant death."

We need to know as much as possible about the wide ranging effects of anything non-trivial that we are introducing into the world. Yes it will slow down progress and innovation but it's also nice to avoid potentially world ending disasters as well. This is definitely not an area where you want to have a 'cha bu duo' attitude.