Everything has economic tradeoffs, triage is needed, but a big problem seems to be a deep set belief that the maintenance you can achieve in x time/budget won't actually pay for itself in fewer issues coming at you later that amount to not paying a cost > x to address. Or similarly is not great enough or frequent enough to create a feedback loop for compounded savings.
I don't want to discount just building things better to begin with though. For all the buggy stuff out there limping along there's also plenty of stuff that simply doesn't need maintenance, and another lot of stuff that only needs trivial maintenance.
Well, maintenance can have many different consequences. It can save more than it costs on disaster aversion, it can save more than it costs on small problems, it can save less than it costs on a disaster or small problems. If done earlier it can reduce the cost of future maintenance by much more than it costs, or it can reduce by less.
Doing it right on the first place has also all those possibilities, and the risk that you may discover that you spent a lot of time doing the wrong thing completely right.
I'd say in a case like this, it's an institutional issue. If you aren't getting support from your organization for incentivizing and clearing the path towards maintenance work, then it quite simply isn't your problem anymore.
Even if problems abound, if the thing will likely get me through my current project, I'll drive that thing into the ground.
I drove my last car for over a year with one cylinder not working until someone ran a red light and hit me.
Should I have fixed it? Probably, but in hindsight it didn't matter.
I have so much coming at me from every direction that maintenance is often a luxury I don't have time for.