Why does XSLT output all text by default?

Hi I had performed a transformation which drops a tag if it is null.

I wanted to check whether my transformation is working fine, so instead of checking it manually, I wrote one more XSLT code which just checks the presence of that particular tag in the OUTPUT XML, if it is null, then the second XSLT should output a text "FOUND". (I don't actually need some XML kind of output but I am just using XSLT for searching.)

When I tried with this XSL code ::

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <xsl:template match="/SiebelMessage//SuppressCalendar[.!='']">
      FOUND
  </xsl:template>
</xsl:stylesheet>

It outputs all the TEXT DATA that is present in the XML file,

to avoid that, I had to write this code::

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <xsl:template match="/SiebelMessage//SuppressCalendar[.!='']">
      FOUND
  </xsl:template>
  <xsl:template match="text()"/>
</xsl:stylesheet>

why did the former code outputs TEXT, why should I insist XSL to ignore all other text? is that the behavior of all XML parsers or only of my own (I am using msxml parser).