He only wants users to get Signal builds from himself, and no one else.
Moxie is most decidedly not against building the code yourself. He doesn't want anyone distributing forks or other clients using the official servers because a) that creates a giant hassle when updating the server and suddenly someone's fork doesn't work anymore and people will blame Signal, and b) if the client doesn't do what they want it to, people will blame Signal even though it's a third-party bug because it's got Signal in the name.
Moxie has publicly stated that he is against anyone publishing a third-party build of Signal.
He has openly and loudly ranted against F-Droid. Of course he's not against users building it for themselves, but he's publicly stated he won't allow F-Droid, or distributions, or anyone else, to build and publish the client, under the name Signal, so that it can connect to his servers.
Read the Signal-Android issues https://github.com/WhisperSystems/Signal-Android/issues/53 https://github.com/WhisperSystems/Signal-Android/issues/127 https://github.com/WhisperSystems/Signal-Android/issues/281 and https://github.com/WhisperSystems/Signal-Android/issues/6292, where moxie publicly states that he will not accept or allow any public distribution of third-party builds of Signal to connect to his servers.
He actually directly reached out to F-Droid, and demanded they take it down: https://web.archive.org/web/20160410152543/https://f-droid.o...
So, how the fuck is what I'm saying misleading?
EDIT: Oh, right, some of the linked issues were purged by him later on. Here's an archive.org link: https://web.archive.org/web/20160410153027/https://github.co...
EDIT2: The real question is why you continue to lie to defend Signal.
On the topic of LibreSignal, a fork with the only change being that it supports notifications without relying on proprietary libraries:
> I'm not OK with LibreSignal using our servers, and I'm not OK with LibreSignal using the name "Signal." You're free to use our source code for whatever you would like under the terms of the license, but you're not entitled to use our name or the service that we run.
https://github.com/LibreSignal/LibreSignal/issues/37#issueco...
Basically, he argues that no one but him has the right to build a client that connects to his servers.
Disclaimer: I personally am critical of Moxie's demands that he fully controls all released client builds, servers, and his use of analytics.