It's not inherently a short term viewpoint, that's just the typical and natural result of adopting this view. Measuring long term impacts is hard. Attributing them is even harder.

Here's a real scenario. I worked for a company that evaluated by impact. They had a cellular modem with known issues in the field. A replacement was designed to fix those issues, but couldn't be backwards compatible. The cost to immediately upgrade the field units was high, so deployment was delayed to a cheaper, later time. One way of looking at this is that the decision saved millions of dollars and that argument was made. After the evaluation and before the deployment, a set of older field units failed in such a way that it made headlines across the country, which would have been prevented by the new units.

So, was the impact of those decisions negative the whole time in an unknowable way? Did their impact become negative as soon as the incident occurred? If the incident was still possible but hadn't occurred, would the impact be different?

People aren't good at evaluating things that haven't happened yet, so they'll tend to focus on the things they can see immediately in front of them. That incentivizes engineers to build things that have immediate short term impacts and discount long tail risks which can't be reliably evaluated.