There may be such a thing as a "nice DSL" but the absurd proliferation of poorly-thought-out DSLs that results from ruby's syntax is really not a positive thing.
Ha ha, my cute gem makes it look like you're making static declarations in a domain-specific language, but what you're really creating is a bunch of code that executes at unpredictable times and in an order that's impossible to untangle! Good luck! On the upside, you can create a trivial example of [something] in four lines of code!
Understandable concern, but nobody can force you to use the said gem, can they? Such fluff shouldn't be a big deal as long as it is not ingrained in most developers' minds.
Besides, it looks like ruby community is currently gravitating towards more javaesque style of programming, heavy on patterns like dependency injection, very explicit, with lots of classes and almost none metaprogramming.
This flaw allows us to have nice DSLs unencumbered with parens.