I'm not proud to say that I've flip flopped on a few products.
Why not? Its OK to change your mind about a product. Sometimes all we need is a little better understanding of what a product can and cannot do. Sometimes our circumstances define what is good and bad in a product. It's no big deal.
People who never change their minds have stopped learning and growing. Education and growth are central to being a human. It is the height of human arrogance to think you have learned everything there is to learn about everything, including car wax. Does that describe you?
BTW, getting back to the original topic about SEPC/GEPC. I think they have lost popularity because they are probably inferior to other similar products, e.g., 1z polishes, VM, PwC, etc ...
In comparision SEPC/GEPC are satisfactory products that are good values, but nothing special.
I disagree. There is nothing inferior about SEPC/GEPC. Every product has its strengths and weaknesses. Most of the products you mentioned are very similar; variations on a theme. They're light polishes with very mild cleaning ability. Some offer protection, some don't. Some use mechanical cleaners, some chemical. Some have more oils and silicones in them. None of this = inferior.
As GeekySteve mentioned, detailing is not a popularity contest. Its about getting the results you want and enjoying the process. Who cares what's popular? This isn't junior high where you have to wear the popular tennis shoe and listen to the popular music to be thought of as "cool". Use whatever you want on your car. No one is going to be talking about you in study hall.