CMS Driven content is always difficult because 99% of CMS-able sites store the content in the database. Migrations in a database of content vs. structure are very difficult. For a long time, I used Concrete5 which had this very same problem. They allowed for an upgrade path and schema migrations for new plugins, but it's never clean.

It's actually surprisingly easy to show a client that the cost to build a CMS site up front is much more expensive, and client statistically don't use them. So I've actually built a bunch of simple sites and had them come back to me for simple updates. They get them done in a timely, non-broken fashion, and I get some return business. You obviously have to find the right client for this, and it's definitely not for everyone...

I started with Java in college, then actually went to PHP, then Flash/Flex/Actionscript3, and now I'm mainly full stack javascript with Node and Angular. I do a lot of R&D, quick prototype stuff so longevity and support aren't a main concern of mine. If something I do is going to go into production, the product I make will usually be handed off to an engineering team as a wireframe/POC to be rebuilt in something the team is more comfortable with. I basically allow a marketing team to have these bright ideas with insane timelines and produce something for a demo or convention without impacting the engineering team's productivity.