I tend to agree for the most part. Depending on your jurisdiction, you may be legally entitled to other (R-134a) alternatives. I am aware that the US EPA has been a 'PITA' as far as accepting 'other' refrigerants into the marketplace. In Canada, the use of HC-12 products is widely accepted and totally legal. Anyone who is even remotely familiar with the pros and cons of R-l34a and HC blends will understand why the former is not a wise choice. But, having said this, the automotive industry and manufacturers such as Dupont have elected to go in one direction. The logic escapes me. However, if you do some research, depending on the State you reside, there may indeed be legal and safer and more efficient (R-134a) alternatives already available.
I recall that some jurisdictions made it illegal to use (HC) refrigerants inside any automotive system that was originally designed and used for R-12 (freon). Okay. But, the way around this was to set up a conversion for R-134a (and then install the HC product).
Finally, I am NOT advocating HC products (such as duracool.com). I am simply suggesting that the misinformed enthusiasts partake in a little basic research before they (blindly) follow the advice of their local mechanic/tech/dealership. thanks.