If the writers make up the story as they go along, it means they don't HAVE A PLAN, which creates situations like this episode where they make poor excuses for something having never been shown before. There's a term called "foreshadowing" where you point to something inconspicuously, and then make it evident later. (such as in Harry Potter, in regards to his scar) When you fail to mention anything about it prior, only to bring it up and say, "it has been this way the whole time" despite having NEVER shown it to be that way, that's called "retcon". The great thing about foreshadowing, is that it can be entirely missed by the audience on the first watch, only for them to realize AFTER the reveal that there were lots of points to indicate the situation being as revealed. The problem with retcon, is that it has its uses in some situations, but poor writers use it constantly. Instead of doing their job and establishing a story with lore (which Lauren did for the first seasons, and the other writers mostly upheld (aside for CotLM)) these writers come up with any idea they feel like and throw any new information they want that is episode specific, and then claim it had always been true.



Here's an example: say there's an episode this season where it is revealed that Applebloom has a second older sister that lives on the farm. The reason that is given for our lack of knowledge of her prior is that "she never leaves her room". Now, I would be pissed at the reveal, because a poor excuse is not good writing. By your "logic" you would be FINE with this kind of reveal. Therin lies the problem. You allow the writers to make up whatever poor excuse they want simply because, while I expect them to follow the established events from previous episodes (you know, this whole thing called "continuity"). If they wanted Scootaloo's parents to have this "job" and always be out of Equestria, they could have had her mention it prior. Like in Parental Glidance, where she's talking about her damn home life. That would have been the perfect time. But no, they're just going to make it up out of nowhere and then claim it was always true.



"If the writers decided to expand upon a concept or a character just because they wanted to, and didn't feel the need or have the time to build up to it, they're bad writers?" Building on a concept or a character is fine, as long as they follow the concept/character they're "building on". Which means they need to STOP changing character personalities for the sake of one episode story. They need to STOP contradicting previously-established lore in regards to a subject just so they can write some other shit.



"And if the writers make mistakes or forget some details, they're bad writers?" The problem with having so many different writers, is that they're not COMMUNICATING, and so constantly bring up new things only to write it off in the next episode. Such as with All Bottled Up following Celestial Advice. Ignoring the abundant retcon in Celestial Advice, Starlight "graduates" from being Twilight's student, and yet in the VERY NEXT EPISODE she has to learn another BASIC friendship lesson (which was terribly executed), and her "graduation" is never brought up again. She still lives in the castle, and nothing really changed until the "school" garbage came around. So what did the writers build upon? They made up some crappy story that lead to an event that couldn't even survive the very next episode. Yeah, that's "great" writing, there. Also, editors are supposed to catch the mistakes that the writers make.



"Look, I'm not saying Scootaloo not having her parents around doesn't affect her in a negative way." Funny enough, they never even touched on THAT aspect of Scootaloo's character, either. They brushed the entire situation aside because "super important job that totally wasn't made up specifically to excuse the absence from 9 seasons of the show".



"If you don't like the show anymore, that's your right, but that doesn't mean you can lash out at people who disagree with you." You mean like you're doing right now?