Imagine this scenario:
I make a popular program called "anime 4 u v1.0"
It becomes trusted, eventually gaining millions of users. I release a new version, 1.01, which has minor changes. I didn't tell anybody I added a phishing program.
.... Yes, decimals matter.
I know this is an extreme example, but there are various reasons things need whitelisting.
As to utorrent, the one listed on the whitelist is the best you can do. For various reasons, no new versions will ever be accepted in the foreseeable future.