Art vs. Intellect
Yes, the two are intertwined; human learning & growth can't be surgically separated into left brain / right brain. It is, however, the main focus of art to appeal through the emotions (not excluding intellect) and the main focus of discourse/ lengthy speeches/ print media/ etc. to appeal via the intellect (not excluding emotion.)
Agitation or Propaganda
Sometimes--agreed-- short, agitational speeches in the heat of a battle are mainly an emotional appeal, almost like a burst of poetry.
"Into the breach!"
Form and Content
The interesting thing is that the content may be the same, but the form different. Let's take Rhinoceros by Ionesco. It was an anti-fascist play that used the emotions--horror, fear, alienation, confusion--to make its point. At the same time when this play was first produced , you could also choose to read anti-Nazi literature which used facts, figures, and ~generally~ a different approach to make the same point.
Art or Entertainment
To me, the role of artists is to illuminate, challenge, show a new way, reflect on our direction. Not just to replay the same already-known information over again. That's the difference, to me, between art & entertainment. Art is mostly enlightening, disturbing, stimulating. Entertainment is distracting, relieving, soothing, ultimately deadening.