My dear Dulset Tarn you are so charming in your disappointment.
These are obligatory "filler" episodes that serve no purpose other than building tension among the characters and trying the patience of viewers, as Hasbro is well aware that controversy creates more secondary marketing as bronies argue loudly on youtube and social media.
Still, we believe you are too harsh with some of your judgment: Maud has never smiled in four seasons, and can't wipe the smile off her face anytime mudstick is near her. It is autistic love, and even though this Princess absolutely despises his hair, we know there is already countless consummation of this pairing in places a Princess will never personally look.
Notice, the message was not that fashion is frivolous but that sales is usurpation of the will of the buyer, dominating them with negative talk they will internalize to drive them to purchase, which serves our master Hasbro's capitalist goals. That Rarity was so accepting of the awful behavior right until the moment the yellow one decreed products must not be sold, let to our second-favorite moment: the alarm and horror of Rarity reflects the dismay of losing our master's best distribution channel Toys-R-Us and brought a sad smile to our lips. Our favorite moment was after the three personas were fired, the instant return of a successfully exocized and repentant yellow pony. Of course this makes sense in a 21 minute story arc cycle to make room for the inappropriate humor you noted, an essential element for the aforementioned squabbling.
Rainbow Dash was simply set up by the evil Applejack. The important aspect of this episode is that elder ponies rule equestria and young viewers we mean ponies must never forget this, if they wish to be included in the old ponies club and cut ahead in line to receive their reward.
We kindly remind the good Dulset Tarn that these filler episodes are also designed to make the passing of the failed original Six ponies more palatable to you as the mixed creature new Six take their place throughout this season.
Pinklestia thanks you for reading.