Warren wrote:

...Personally, I think it all goes back to Dow Chemical's use of the
slogan, "Better living through chemistry."...


I thought that was DuPont's slogan.

Thought I'd add my couple pennies:

There is a difference between a substance produced in nature and the
same (by chemical structure) substance produced synthetically. The
difference is not really in the substance itself, but in the byproducts
of the production of the substance. Some things can be produced
synthetically without any problem, but others produce byproducts that
can be toxic. The trick is in knowing what substances are safely
produced.

As far as using "chemicals" on your garden, there is a place for them.
Chemical fertilizers certainly work, but since they are generally
soluble, they fall into the remedial, or quick-fix category. They will
perk up a plant, but they will leach out of the soil fairly soon. A
better option is to use fertilizers that hold the nutrients in place
until the plant roots act on them to release them. This includes compost
and composted manures. I know there are chemical fertilizers that
release slowly, but these are generally timed-release types: soluble
fertilizers encapsulated in polymers that release the nutrients in
response to water and ambient temperature, whether or not a plant is
there to use them.

Chemical herbicides or natural herbicides? Both can alter groundwater
quality. If you have to kill a weed, how about a hoe? If you have a weed
in your lawn, you can dig it up. In extreme cases, spot application of
herbicides will be the only thing that will work, but broadcasting weed
killer over your lawn is (1) wasting weedkiller and (2) contributing to
non-point-source water pollution.