- If I upgrade to El Capitan (which may not happen since this is the first release in a long time where I am not seeing worthwhile benefits to this version of the operating system) I will always turn rootless off in the future - your application isn't the only one I have installed that is affected by this change in system protection.
- Users that are looking for a better Finder experience, clearly have vested interest (and likely capability) to turning this feature off.
- While many may not understand what it takes to get TotalFinder to currently operate on pre-El Capitan, asking the public to educate themselves on the risks and benefits is never something that should hinder your offering - that is what it is - an offering, not a force-feeding - no one has to use this software - it's their choice.
It's commendable that you care for the support of the software to the customer, that's not being questioned here. However, ultimately the user owns their machines and are responsible for installing the software on their computer.
Now I understand that you're at a stage in your career where you don't want your business to have to fight the battle any longer - that's your prerogative. At least, would you consider making the code open source so that others can continue to support what amazing work you've achieved thus far?
I have paid for this software to be developed to the current achievements that it has acquired. I am extremely happy with it, and I would never begrudge you for making it open source. Other paying customers, should understand that the money they paid went to the development and support in the past to get it to where it is right now.