In all seriousness, I'm sympathetic to the idea that we should be careful about exactly what sorts of advances in biotech should be patentable. There is a legitimate debate to be had about how big the change should have to be to gain protection because obviously all new work is based on the past work of others (and mother nature herself).
But I don't think that admitting that we should be careful about where we draw the line means that we should have no line at all. There is legitimate biotech work that people are doing. Hard work. Expensive work. Good work. If we want this work to happen, then it makes sense to put in some sort of legal protection for it.
In the Monsato case, the patent covers every instance of those genes, whether they came from Monsanto or not.
Here's an article on the differences between copyright, patents and trademarks:
There's plenty of other entities that would be interested even without patents. Large agribusiness would be interested in increasing yields (your 'bigger banana'). Health organisations would be interested in dietary components (your 'vitamin A deficiency'), and it's not like research universities are forbidden from doing agricultural research.