Overall, this leads to less herbicides being used because Roundup is so effective. Normally a farmer is forced to use many applications of a variety of herbicides (some with proven problems for humans.) In comparison a couple blanketings of Roundup is preferable.

The problem of Roundup resistance and decreasing genetic diversity is a serious concern though.

Initially, maybe, but i've read glyphosate resistant strains of pigweed quickly took over have been causing big problems. For many farmers, pigweed was the catalyst for them moving to roundup ready crops. Apparently Monsanto is trying to push Dicamba resistant crops now (see above).

Herbicides aren't the only solution for that problem. Some practices such a tilling, for example, churns up a bunch of weed seeds which exacerbates the problem (and others).

Oh yeah. I totally agree that we should be concerned about the long term consequences of herbicide resistance and that Roundup ready crops will contribute to that problem. We should probably have some national standards for sustainable agriculture that are backed by science and enforced by the government. Just like we should have a national strategy for handling antibiotics in order to minimize or slow resistance.

But this is not a problem unique to Monsanto, Roundup nor GMOs. If Monsanto was gone tomorrow, someone would just jump up in their place, different gene, different herbicide, same problem. Most people who work at Monsanto probably think they're doing something good for people. They're selling the most modern solution to an ancient problem and keeping the green revolution rolling. Are they aware about the concerns regarding their product? Probably, but just like most people they're a bit willfully ignorant of the consequences of how they earn their living.

In the end, I don't think the solution is to throw the baby out with the bathwater and get on the fast train to fruit loop town with the no GMO, Monsanto is evil, "organic" only, all natural kool-aid drinkers. Having a standards body in place that makes sure this technology is applied responsibly is the best solution in my mind. Of course ensuring regulatory bodies aren't overtaken by zealots or shills is always a problem but I'm not sure what else to do.

And your imagination regarding genetic diversity would be wrong: Roundup ready genetics have multiple generations, each with a smaller footprint in the genes of the host plant. Also, it's not as if this is being added to a single strain of soybeans or corn: There's quite a bit of genetic variation between different seeds with roundup ready genetics. It has to be, as the corn that has the highest yields in northern Montana is different than in Missouri: you have over a month in differences in relative maturity. Something similar happens in soybeans. If you want little genetic diversity, go look at plenty of non-gmo, completely Monsanto unrelated fruits (They just have a small veggie department).

Now, one has to be quite incompetent at spraying glyphosate to have significant blow over across the edges of fields: it's a very well behaved chemical in that regard. If you wanted to both make Monsanto look bad in this topic, you should forget about glyposate and think Dicamba. I won't bore HN with all the details, but even in Monsanto's new formulation, which supposedly makes the risk of hitting neighboring fields far lower, just picking a day where the weather isn't exactly right for the spray, or poor technique application, will lead to major damage in neighboring fields: The results might have been good in the lab, but they are not great in practice. It's arguably Monsanto's biggest piece of existential risk.

One or a few strains per region isn't exactly what I'd call a healthy amount of biodiversity.

I don't know much about the Dicamba topic, but it looks like a nasty herbicide and Monsanto is producing GM seeds that are resistant to that, probably to overcome the natural resistance to glyphosate that pigweed developed. It seems like there is a lot of controversy around it. Care to comment more on that topic? I think there are some interested readers that you won't bore.