Lua attracts a lot of devs with a pretty low-key, humble attitude. If you go to a Ruby mailing list and ask people "should I use Ruby for x?" the answer will mostly be a resounding "yes." On the Lua list, people will often tell you "that depends," will advocate for lots of other languages, or even tell you "no, I don't think so." I think that's in part because of Lua's history as an embedded/glue language: many programmers who work with Lua don't use it as their primary language, and so they don't have the same urge to hard-core advocacy and evangelism that many other languages' users have.