It sounds outrageous until you realize:

1. The F-Droid team has a set of checks that they perform:

  a. Is the app open source?

  b. Does the app do things that the user might not want? ie access non-free services

2. Sometimes, to get around #1, special forks of projects are created so that apps can be included in F-Droid

3. The volume of new applications seem small enough that the F-Droid team can keep up just fine. The only problem I've seen w/ F-Droid resource problems are updates that take days to show up

4. As other have mentioned, you can opt out by running your own repository. Nothing is locking you into the F-Droid primary servers

I appreciate the additional curation F-Droid brings and I love the fact that I can tell other people to use F-Droid unreservedly and know they won't get anything spammy or freedom restricting