In tiresome tirades tendentious why do sound so pretentious?

Our deluded Prime Mover
acts arrogant & contentious
seeking room to maneuver
with pithy prancing pretentious

Readily spouts what’s trite
mixed with random invective
Blindly claims to be right
while facts, logic deflective

Keeps up tiresome tirades tendentious
but aren’t we all sometimes sententious?

+)
sententious = full of terse pithy sayings & axioms