I disagree with the analogy. Need for repairs arises because of the natural decay. Tech debt is a consequence of the decisions made at implementation or even planning stage. It's more like forgetting to order a plumbing connector and using duct tape instead. Except in software there often isn't any forgetting involved and the actual connector is never ordered.
A lot of tech debt is self-inflicted, but not all. Decay is induced by external forces and the same thing can happen in software, e.g. when underlying platforms change.
Mobile apps are pretty high maintenance because you often have to change something with new OS releases and want to roll out an update. You can abstract over the platform but that is in itself costly, so there is a tradeoff.
