So I don't pretend to know everything but I will give you my take on genetically modified foods and what the big deal is.
I am most definitely pro-science and GM foods are an amazing achievement to be able to produce high yeild, low disease crops - just by shifting around a few genes!
In essence, if we think of this in 'human' terms it is like moving/changing genes around to ensure the 'child' is strong, has healthy bones, skin, eyes, and low probability for disease. So what is wrong with that? Nothing really, if something is less likely to get disease there is less need for pesticides, if there are higher yeilds in crops then farmers are ensured good crops every year.
The problem with GM foods is not the food but the politics. One has to think logically about the investment of money to make a you beaut' 'perfect' crop - who owns that GM seed?
Large companies will invest money to make the perfect seed then have farmers grow it for them. The farmer is locking into using that seed and selling to that company - only! If the seed it the property of one company the farmers cannot shop for the 'best price' for their goods they are stuck with what the company contracts the price to be.
Takes a lot of the competition out of the market, further more, I think it takes a lot of the 'farming' out of farming. While GM crops are the way of the future to feed out ever increasing population the seed that is produced from it 'should' be public property, rather than private.
Otherwise those 'perfect' crops will always sell to the company who made it and who else is left to sell to - the best price should really go to the best crops, but at what cost?