&gt; Why doesn&#x27;t language power make a difference in practice?<p>Depends on your definition of &quot;make a difference in practice&quot;.  If you mean &quot;make the language become one of the dominant ones&quot;, yeah, that doesn&#x27;t seem to have happened.  Either Lisp is less effective in the large than one would expect from its power, or it&#x27;s less powerful in practice than people think, or power has almost no relation to language dominance.<p>But if you mean &quot;make a difference to the user&quot;, well, it lets the user more easily write the program that the user wants to write.  In practice, that makes a difference - to that user.