Too short a delay is annoying when you aren't looking for it
Too long a delay is annoying when you are looking for it
The latter is more painful/irritating in my view, i.e. not having something you want is worse than sometimes getting something you didn't want
I feel the opposite. Because it depends on your perspective: which is worse, a slight delay before you get what you want, or having something forced on you that you didn't want in the first place? I think the latter is worse.
Keep in mind, while the audio tooltips can be small, the movie tooltips can be HUGE. As in block half the UI huge. Having one of those pop up when you didn't want it is extremely annoying.
The situation is worse for people with trackpads. When using a trackpad you often have to pick up your finger to reposition, and this means you get unavoidable unintentional hovers. And that provokes things like tooltips with short timeouts, and also those flyout menus on the tabs, that have an even shorter delay; they fly open so fast it's hard to move your mouse away without them continually expanding. I'd love to be able to set those flyout menus to be click activated.
I think arguing about a default time is a trap. The IS no default time that satisfies everyone. I timed the old timeout at 1 sec, not 1/2 sec, by the way. Enforcing just one value just pisses half the people off, whether it's long or short.
Pretty much everyone seems to have been asking for configurable, but oh well.