Well, it means my product is going to be superior since I went the better, if less well known, architecture. It's not like erlang is a little unsupported side-project of a language, it's actually older then javascript if you count the time period before it was open-sourced, and only a few years younger if you don't, and is used extensively by many industries.
Also, just because javascript the language is more well-known doesn't mean javascript the server architecture is more well-known. I would argue it isn't; when people want a highly concurrent, solid server, erlang is always mentioned.
Lastly, erlang is a pretty easy language to learn. I had the basics down in a day, I had a prototype pubsub server that could handle 50k connections in two. The syntax is a bit strange, and honestly it does get in the way sometimes, but it's not hard.