The ability to understand and maintain inherited projects is more valuable than the ability to create new greenfield projects.

In terms of value as an income, then for a consultant this is most likely true - for staff working in a megacorp not so much.

And often, it's not the code that is the issue. You understand the code perfectly fine and can edit it easily. The main issue is always finding out the "why" so you do not remove any Chesterton's fence while coding for a new change request.