The real problem isn't breeder versus shelter-adopted - the problem is people who do not think about long term responsibility when they decide to take home a pet.
The only way I learned this lesson is when I decided to buy a rat as a pet. I was 21, and I was living in a flat that banned pets. I thought I could handle a little rat, but the little guy hated me and I ended up hating him too. After a few days, I tried to return him to the pet store, but of course, they wouldn't take him back. I put up fliers everywhere to give him away, but no one wanted him. I called the animal shelters and was told they wouldn't take him. Then I was told that we were going to have a flat inspection. Knowing pets were banned, I realised just how stupid I'd been.
I decided to release him outside, in a wooded area near water. I dumped him and his rat food there and left. I told myself that he'd live quite happily for a while, but I was pretty sure that since he was a pet rat, he probably wouldn't survive for long. I have never felt so guilty about anything in my entire life. I should've known better at 21 years of age. When it came down to it, I was selfishly naive at every single point. I still get upset thinking about it.
When it came to getting our two cats, I remembered the rat and I was very careful about what I did. I knew I'd always wanted bengal cats, so the choice was either a breeder or the off-chance that I could adopt an abandoned one. There is a group of breeders in the UK that also rehome bengals. We looked for one to rehome but everytime we tried, they were already gone. In the end, we bought one from a part-time breeder who was a veteranian, and one from a breeder who also ran a cat boarding facility.
Bought both of my bengal cats from breeders. I don't feel bad about it in the slightest. I wanted animals that had been treated well from the moment they were conceived to the moment they ended up in my home. I wanted them to be healthy so that it would be less likely that they would need medical care for a chronic illness or something they pick up from a shelter. Call me heartless if you like. They both have a good home, are spoiled beyond belief, and are my fat happy babies. They only get fed HiLife catfood and are indoor-only cats.
In my opinion, no one has the right to tell me I was wrong to have chosen to purchase cats from reputable breeders over adopting. Bengals are f'king hard work but we've committed ourselves to them and would do anything for them. They aren't like normal housecats and require a great deal of stimulation and attention to stay happy. So long as I look after them and ensure that they don't produce unwanted kittens (both are neutered), I don't feel I owe anything at all to an animal shelter.
If I choose to support a shelter, whether in volunteer hours, donations, or even adopting a creature, it won't be out of a sense of societal guilt, which the OP (the one Shimmer copy/pasted, not Shimmer herself) obviously wanted to impart on all of us. I am not responsible for other people's mistakes, only my own. And only my own cats, for that matter.