There is a few reasons why I don't:
1. It may not give a carnuba "glow"
2. Sprucing up your paint with a paint cleaner with a glaze or light polish every few months and topping it with a sealant or wax (or both) really adds pop to the finish IMHO. OC looks best day 1. There is no way really to "refresh" it.
3. If you do any "work" (polishing) on the OptiCoat its impossible to know if you've gone through the coating for sure. With traditional products, this is no big deal.
4. While the product does work as advertised, not everyone gets the results as advertised

. This could be user error, peculiarities to the paint, or an environmental issue not predicted by the manufacturer. For whatever reason, OC seemed to only last me 6 months. Prior to application, I did multiple IPA wipe downs (70% undiluted). I don't know why it didn't last. I do know I topped it with many spray waxes, so in not sure If that may have messed it up.
5. A lot of us like trying new products and aren't looking for the longest lasting product. Looks may play more of a role
**** OC seems to be holding up very well on the wheels of my 2 cars. It's really working well there. I may give it a go again next winter for the paint using only Optimum products to prep.