I've read quite a bit on the AFDA site. They cover commercial food production as well as home preservation, so there is a lot of detailed information on the risks involved in preserving food, the bugs that pose a risk and the ways of ensuring safe processing.
It is similar to official sites from UK organisations involved in food safety. It covers every eventuality and contains a wealth of information. There have been incidences of botulism in commercially produced preserved goods both here and in the US that are documented on these sites, plus reports on incidences on botulism in home canned goods. I don't know the circumstances, so can't make a judgement on whether hygiene or lack of knowledge was the cause. Maybe it was just bad luck that a food stuff was already contaminated, looked fine, smelled fine, but made people ill.
Knowledge is power in my book, so having read the official sites and quite a bit on homesteading and food preservation sites, I can then make my own mind up.
It is the same with rules about chickens here in the UK. The official rules say feed nothing that came out of your own kitchen. This came about after poor farming practises here, where a farmer was feeding food waste to pigs, led to a massive outbreak of foot and mouth. Again, I can see the sense in the advice, but I can also use common sense when looking after my own little flock.
If you are someone who is freaked out by the chance home preserved foods may be dangerous and have no confidence that you can do this safely, it probably is best you continue to buy your food. If you have the intelligence and common sense to take on board all the information and move forward from there, all power to your waterbath (or pressure canner)