>>717734382
>non FE characters
My man, It literally says "FIRE EMBLEM" in the title. the game fucking screams it when you open. This has never been a reasonable thing to hold against the games characters.
>and 1 specific series
Ideally it wouldn't, and shouldn't.
In a devils advocate defense of IS, It's a gacha and their a business. They should ideally, from their perspective, focus somewhat on things that sell.
The issue is there are also hundreds of characters in the franchise, most of the playerbase has likely never played more than half the series, and because everyone has their "literal who" favorite character, everyone is going to get upset at every banner. Don't get me wrong IS is certainly incompetent in a lot of these areas, but people also shit on them a bit unfairly.
They're not going to focus on selling multiple Thracia banners, a game that had an infamously shitty release and was never translated, over the best selling mainline title, just to be fair. It's just not realistic.

TL:DR
The "FE" in "FEH" stands for "Fire Emblem".
no business is going to focus on selling multiple variants of an obscure product over their biggest seller, it's not pragmatic.