The parsimony principle is typically used when reconstructing phylogenies because
$a$. evolution is nearly always parsimonious.
$b$. it is better to provisionally adopt the simplest hypothesis capable of explaining the known facts.
$c .$ it is easier to handle parsimonious data with computers
d. parsimony works well for all kinds of traits, both morphological and molecular.
e. parsimony was used before computers were available and it continues to be used even though new methods are better.