Comment regarding xsl:attribute

Concering section 2.7.2.3 "Creating Attributes with xsl:attribute" in
the
XSL specification, I find the following statement overly restrictive:

 * Including nodes other than text nodes in the value of an attribute; 
implementations may either signal the error or ignore the added nodes.

It seems useful to me to allow nodes within the xsl namespace to
be contained within xsl:attribute.  Especially xsl:text, xsl:counter,
and xsl:number.

In my particular case, I was hoping to create uniquely numbered 
identifiers using a counter.  Something like this:

<xsl:counter-reset name="myCounter">
<xsl:counter-increment name="myCounter">

<p>
<xsl:attribute name="id">myID<xsl:counter name="myCounter"
/></xsl:attribute>
Test
</p>

<xsl:counter-increment name="myCounter">

<p>
<xsl:attribute name="id">myID<xsl:counter name="myCounter"
/></xsl:attribute>
Test
</p>

would produce

<p id="myID1" />Test</p>
<p id="myID2" />Test</p>

Is there any compelling reason why elements such as xsl:text,
xsl:number,
and xsl:counter could not be legal children of the xsl:attribute
element?

And if this cannot be done, is there an equivalent legal alternative?

Thank you very much,

JOHN
john@ncompasslabs.com