To say Katherine & Michael stopped caring about the series that built their career, that bought them a house and secured their kid's college education, and ran for half a decade, is, sorry to be blunt, worthy of insult.
Come on. Saying something like that is begging for a snappy retort. It's nothing against Escafil personally, just...they cared about the Animorphs story arc. They just did. It's one thing to take issue personally with the way the ending played out, but don't play off your dissatisfaction by making accusations they stopped taking it seriously.
They rushed Everworld's final arc. They finished Animorphs with the caring and finesse it deserves.