I think it's legitimate to first use well-known platforms where people are already registered, especially in such an early development phase.

This has not much to do with dogfooding.

It is called network effect, which is a significant driver. It incentives entities to join networks where their target audience lives. This does not stop those entities to educate the said audience about topics which are in tension with the network hosting the conversation (e.g., decentralised vs centralised systems).

We'll happily use Locutus for those things once it's ready ;)