Because when you are trying to put out a fire, the fact that the fire extinguisher can fall over a year from now, is a really irrelevant reason not to put out the fire.
This is the kind of thinking that eventually leads to PHP; an everlasting stack of always exploding fire extinguishers.
"memory leaks here aren’t too relevant" will be a real candidate for Rasmus' epitaph
That’s only the kind of thing that you can put on cruise missiles. The memory leak will crash the program within 10 minutes, but the cruise missile will have detonated within five so it doesn’t matter.