Why They Harm Us
Due to the fact that GMOs are created by modifying genes, many feel that this may cause a new allergen to form that people are unaware of. Along with this, GMOs contain antibody-resistant substances in them. When we consume GMOs there is a chance that the bacteria in our body can pick up these antibody-resistant substances; therefore making us resistant to antibodies.
Owners of Small Farms
GMOs are expensive and costly; therefore, farmers that own small farms may not be able to plant GMOs. However, bigger companies may be able to afford GMOs, therefore enabling them to sell tastier and more physically appealing crops. This will hurt sales for small farms because people will favor buying GMOs from the bigger companies.
If we breed the exact same crops over and over again, this eliminates diversity. Therefore, a lot of the same plant will be grown. If there is a disease going around that targets a specific type of crop, then farmers of a monoculture (of that crop) will be severely affected because many of their crops will be destroyed.
People do not know how GMOs will affect the environment around them. Although scientists claim they have been "tested", they have only been experimented on in a lab setting and not an actual farm. Also, after a while, insects adapt to the GMOs; if they become resistant to pesticides in GMOs then that we will be in a dire situation. Along with this there can also be "superweeds", which adapt to the herbicides around them (GMOs).
In For the Profit
Many biotechnology companies claim that GMOs are better than they really are, just for the sole purpose of earning more money. Along with this, GMOs are being distributed and sold too quickly, without enough proper testing. The FDA, EPA, and Department of Agriculture are also being too easy on the biotechnology companies in their investigations.