I thought it was brilliant.
And Dash hasn't abandoned her friends. Her element in one episode has certainly been in conflict with her desires and that is a long-term thing, Chem. She's wanted to be a Wonderbolt, but now... she's realizing that dream may not work in the long run. The shine is wearing off the Wonderbolts. Further, if the girls were in real danger from Discord in "Three's a Crowd," would Dash have been there? Buck yeah!
Finally... Today was a case of simply being enthralled. And friends are occasionally thoughtless.