[Maxima] Should opproperties functions do more simplification?

[Barton Willis]

Should %o2 be p(z) + p(x) * p(y)?

(%i1) declare(p,additive,p, multiplicative);
(%o1) done
(%i2) p(x*y + z);
(%o2) p(z)+p(x*y)  <-- could be p(z) + p(x) p(y)

(%i3) ev(%);       <-- needs an extra ev. Why?
(%o3) p(z)+p(x)*p(y)
Barton