Ah, so because I use it I'm not a person. Gotcha. [/sarc]
Usage of a language is irrelevant to the discussion of language features, or it's 'style'. There are many unpopular languages which I would like to learn some level of proficiency [more than just "I've heard of..."], precisely because, if nothing else, they will give me more tools & understanding to address the problems of problems [which programming is]
LISP [functional programming],
Prolog [Logic/goal-based programming],
Forth [advancement/development via continual addition of 'words'; stack-based],
PostScript [addressing imaging issues; stack based],
Snobol [string manipulation; from reports an order-of-magnitude more 'powerful' than regex];
these have [vanishingly?] small user-bases [in general programming] but are interesting in 1. what they allow, 2. how they address programming in-general, 3. how they address their own 'focus'/specialty.
To dismiss (out of hand) a language because it is unpopular from qualifying for consideration in a discussion about some general-attribute indicates nothing about the language brought up, but it does say something about you, and not really a good thing: that you are a "me too" sort of programmer, going with the flow and, more importantly, not thinking about your trade -- and if you are not thinking about your trade, then how can you be trying to improve it, either by improving yourself or by improving a language, or even improving methodology ("best practices")?
What are you? Five? [Protip: The giveaway on that is the </sarc> tag.]
Playing with languages isn't the same thing as coding in them. I've coded in 370 Assembler, various micro processor Assemblers, all dialects of FORTRAN since FORTRAN IV, Algol, Pascal, Delphi, PL/I, APL, Prolog, C, C++, C#, Objective-C, Java, and most known idioms of Basic. FOR MONEY. Let me stress that: FOR MONEY. If you aint doing it for money, you're just a hobbyist. I don't have time for hobby languages.
And I'm not the least bit interested in lectures about "best practices" from pedants who don't know anything about my code.
The fact that you think fooling around with hobby languages makes you a "sophisticate" thinking about the "problem of problems" says more about you than it can ever say about anyone else. See how that ad hominem thing works?
Read Rudin, or Herstein or Berkoff and McClane, Spivak or one of the other great mathematical expositors if you want to vacation in pure abstraction, not stupid kiddie languages. Read Cohen's book on the Continuum Hypothesis.
Lisp? Seriously? Lisp. My gawd.