Why don't you let loyal customers that laid out a premium for your products download all new versions of the products they purchased to offset residual costs? Instead if you join the subscription program you are laying out money for the latest so your purchase is relatively worthless because you have a separate license. It wouldn't cost you a dime to give those who paid to own a better discount at upgrading their products to the latest version.
Companies that do not treat their current clients with respect will lose their business to those who do.
I talked to someone at adobe and they told me they are working on extensions that are more advanced than WebAssist. I can't wait to stop giving my hard earned money to you.