Populous who bash scientist tend to not think critically...
Foods that tend to be genetically are new to the human diet and hardly edible anyway. These foods are only common because of us, so no matter what we do with them we will impact the environment.
People already eat garbage. Products that don't have any negative externalities are being made, and many organic products can survive on their own merit, while many other organic products aid the survival of parasites and trigger allergies.
We evolve to fit our environment, we will evolve to live with GMOs, maybe even individually adapt.
New mutations show up all the time. Most genes don't do anything because they are just evolutionary leftovers. Sometimes we find the same gene still working in a relative, so we take a set of genes from the relative to get the redundant genes to do something, and often they do something that can be sold, but the gene set we have added to has evolved with out the new genes, kind of like a new mutation evolving and being a negative at first before newer mutations help it out. (Welcome to my mind)
Some life forms are more prone to getting new genes and mutations. Viruses really genetically modify between species with out planing.
I'd bet that middle class nerdy westerners will soon have the ability to genetically modify their own house plants and pets and fairgrounds and conventions will have all kinds of interesting specimens. Monsanto may mutate and be like a taime wal mart amongst all the working class competition. Millions of lower and middle class nerds networked internationally with a Silicon Valley style upper class, making safer foods that can work for urban homeless, pats that need less food or can eat garbage, parasite like organisms that make needed drugs instead, cyborg nanobots that protozoa that surround human cells in extreme conditions to protect from cellular parasites and regulate metabolism. Nanotec designed to communicate with brain cells and nerves. Surgery prep nanites. Cells modified to communicate with naites. Bionanites that heal cuts and watch for cancer, or in case of experiments find use for cancers. Computers and cell phones with nano and genetically enhanced brain cells in them. Imagine going into wal mart, an air port, the local mall or any other venue and placing your hands into a biotec computer to get you naotec updated by your favorite healthcare providers. The computer will even communicate with you based on your personality type.
How about people who just find a way to make the same product without patent protecting genes. There would be genes made to prevent reproduction because the product sold may never be the final product, but wouldn't they find better genes latter on. Besides, even the GMOed seeds could be mutated to reproduce.... and it seems even possible for the patented genes to mutate yet still provide the same trait.
In reality government is just a bunch of people doing a bunch of stuff. Government could decide that it is irrelevant a virus mutated some Canadian guys millet crop with genes from a Monsanto seed spill but people were just obeying a judge and the enforcers are the one's who are responsible and we should keep our eyes on them instead. Some one at Monsanto was being a Dick and when if our own businesses have that we should fire that guy.
Not all GMOs produce food. Some are fast growing wood. Some make drugs and medicine. Some are fabric. Some are industrial chemicals and plastic. Maybe some will be useful in mining and organ transplants. Some could help us clean or give us cheap energy.
Just because you say YOU haven't seen it doesn't mean it doesn't exist. People who hate new technology don't understand it. I'm not a scientist but I outrank you.
"The purpose of GMO companies is likely to maximize profits at people's expense and to monopolize the land so that the common people won't have access to either land or their own seed etc." Profit is a worthy motive. Anything else and I'm left wondering if they are filled with the evils of altruism and all its unintended consequences. If the people lose their land then they are left to make wages insted of haveing to worry about lose. They will be working among scientist and be at the cutting edge of the economy and new technology.
"It would surely be possible for GMO crops to be an improvement for health, if the scientists were not working for corrupt companies."

That is very irrational. Everything can kill you and few foods will kill you in large amounts. Like how could organic farmers afford to avoid their crops mutating and giving you cancer. They grow their stuff in dirt. Dirt is made of everything good and everything bad mixed at random. Dirt genetically modifies the stuff growing in it being that much of the dirt is alive. The corrupt companies know what they did with their crops, and when they told you, they missed that they weren't speaking your lingual, and you misinterpreted that as mad scientist intimidation. In reality they are just selling dumbed down products that might make investment money for brilliant works of art when they can focus massive budgets and very advanced technology at... what not.... but they must be Satan because i always thought they were Satan.
"Do you consider patents on plants and animals moral?" Patents can't exist. Reality is stronger than government. We need to shift the focus to specific individuals.