Why has XSLT never seen the popularity of many other languages that came out during the internet boom?

<Really>
    <No>
        <fun/>
    </No>
</Really>

<xsl:variable name="lcletters">abcdefghijklmnopqrstuvwxyz</xsl:variable>
<xsl:variable name="ucletters">ABCDEFGHIJKLMNOPQRSTUVWXYZ</xsl:variable>

<xsl:value-of select="translate($toconvert,$lcletters,$ucletters)"/>