A few years ago a story made the local headlines when submerged metal spikes were found at a beach in a local park:
When a wading man found metal spikes in the Green Lake muck last week, Seattle parks officials were horrified and said there couldn't be "any other explanation than malice."
It took about a week for the real story to emerge, relevant part:
Kathy Whitman, city aquatics director, confirmed Friday that looped metal spikes were used in the early stages of milfoil control in the 1980s to hold down plastic sheeting, and the spikes found this month may be those devices.
The events demonstrated a reliance on individual, siloed knowledge and how such systems decay over years. And it's not just city departments; more and more things (clothes, cars, information, even buildings!) are rarely expected to last for decades.
Sometimes it's truly overkill to build too much sustainability into a system and indeed, too much future-proofing can actually be harmful, but that's a whole subject in itself. But in moderate terms, it's rarely a bad idea to at least consider how a system will look a year, two years, five years and ten years from now. The thought exercise of revisiting something a decade later is often sufficient to overcome the the temptation to take the most expedient, short term path.
The real art is creating an environment and culture such that the default behavior considers sustainability from day 1, avoiding costly retrofits later on.