The longer a plan takes, the more things will change before it comes to fruition. The world will be different tomorrow, and different again each day thereafter. Therefore, it is perfectly rational to make plans for the near future, but to wait for more information before making plans for the distant future. We can argue about the precise degree to which we should favor the short term vs. the long term in our plans, and there are some reasons to think that people have it mis-weighted, but simply telling people to "favor the long term more" won't do because it's possible to overshoot and neglect the present.