As much as I like the Cavendish banana I've been eating for years, having clones of a single variety of seedless bananas is not the best way to have a healthy industry protected against the Panama disease... Even with genetic engineering, it's good to have access to the
biodiversity provided by the rapidly disappearing wild bananas and older traditional cultivars.
Actually, Round-Up ready crops don't have higher yield than the conventional version (e.g.
this), the profitability to the farmer comes from saving money elsewhere (e.g. less labor), not higher yields. And if you look up government reports like
this one, you realize that the effectiveness of GMOs varies from one place to the next (depending on local conditions). That's not to say that GMOs are bad, evil, or anything, but that one should remain critical of technologies and sellers of "one-size-fits-all" solutions. We should be critical of the claims of organic farming sellers and promoters, but so should we of the GMO crowd. Don't dismiss a side without digging further (to make sure you're not rejecting a strawman), don't embrace one without digging further either. That is what skepticism is about.