I understand, although the original StackOverflow question predates even
Java 2.0, I think.
One thing to keep in mind, however, is technology rot. I don't think it should be all that difficult to migrate from JSF2.0 to JSF2.2 or 2.3, but software doesn't last forever, no matter what Management thinks. It decays from the outside in. It's the classic band-aid case where you can either suffer many annoying small jerks or one big agonizing
jerk. With the added caution that the pain - and cost - accelerates as time goes by until, if you pardon the metaphor, you have to yank so hard that body parts come off.
The secret of how to be miserable is to constantly expect things are going to happen the way that they are "supposed" to happen.
You can have faith, which carries the understanding that you may be disappointed. Then there's being a willfully-blind idiot, which virtually guarantees it.