An answer from viners on r/btc:

> The problem is that the majority of people only read one sub and don't know that others exist.



My answer to that:

I think many r/bitcoin people know that r/btc exists, but when you look at the frontpage of r/btc, ALL posts are related to only two topics: BU vs segwit, or r/btc vs r/bitcoin.
This is unlike r/bitcoin, where, you could argue, MOST posts are also related to the same two topics, but at least there is a bit more diversity in the topics.
Therefore, I think we have to improve the quality of r/btc before we can expect most r/bitcoin people (most of the bitcoin community) to join r/btc.