What soundcard do you have anyway? I wrote this cuz I assume that your card is cheaper one with no ASIO drivers. (no offense)
You are right. Only Ableton live can use ASIO. Music players don't need low latency drivers.WHich of those specifically used ASIO as opposed to MME or WDM drivers? WIndows Media, for example, doesn't use the ASIO drivers. I doubt that Sound Forge does, but would be interested to know... in the same way that Audition doesn't use ASIO, because as has been pointed out, for the typical functionality of the program ASIO simply isn't required/an issue.
On another note about sharing ASIO drivers:
I already have ASIO but I just downloaded Asio for All anyway to experiment and I tried to set-up 2 apps using the same asio drivers, it doesn't work just like on my card. (audiophile) This confirms that ASIO drivers can't be shared.