"In the agile world, success is all about business value - regardless of what was written in a plan months ago. Plans are made, but updated regularly. They guide decisions on what to do next, but are not used as a success measure."
so, answering your question with that in mind, the focus should be on business value. does maintenance provide business value? do new features?
Yes, and yes. In a mature company, maintenance provides more business value than new features. To list some of the maintenance activities:
- incident response. It is not uncommon for a company to have losses in the tons/hour or millions/hour if the primary process has a malfunction.
- organizational changes. No software exists in isolation; changing requirements in a connected component may require changes in your software component too. Developers may think this kind of work is feature development, but from a business point of view, it's simply maintenance. Because of the dependency by other parts of the company, this kind of work usually has stricter deadlines than "new features".
- Predictive maintenance. Identify weak points in the current setup, and isolate of strengthen them before they cause an incident. This includes evaluating technical debt. The value to the business is in risk minimization, and the rationale for this kind of work is predicated on proper risk accounting.
These requirements and processes are part of any proper engineering discipline; these are not marginal issues.
Why not? Because the customer already paid. Because Dev wants to focus on getting new customers instead of catering to the ones who have already forked over the money.
"What do you mean feature X isn't working for the customer? It's working for us in our lab. Anyway, we're all focusing on getting new feature Y working in our lab now." - This is the attitude I am sensing below the surface. It's frustrating.