alt Hacker NewsWhich part? The assumption is that when you `$TOOL install $PACKAGE`, you run (i.e. import) `$PACKAGE` more than you re-install it. So there's no point in slowing down (relatively less common) installation events when you can pay the cost once on import.
(The key part being that 'less common' doesn't mean a non-trivial amount of time.)
Why would you want to slow down the more common thing instead of the less common thing? I'm not following that at all. That's why I asked if that's backwards.