I was almost bounced by HR during a screening interview a couple of years ago when they found out I had been doing maintenance work for the previous six months. I had to explain that it was a tiny part of my overall work experience. The hiring hypocrisy is strong.

Also as you point out, getting funding for preventative maintenance or continuous improvement is extremely difficult in a corporate IT environment, especially if there isn't a product owner to advocate for the system and to secure funding. Although I do believe you need a product owner to drive the work to ensure it delivers business value, and not have it driven solely by developers.