Only played the 2016 one, Absolution and one of the others (might've been Blood Money, don't really recall, was at a buddys house). Can't say the storys have ever really struck me as more then hokey junk to facilitate the game. 2016 does have an overarching story, anyhow.
The episodic thing doesn't end up hurting it from a gameplay standpoint. The game (and the other Hitmans I've played) were split into levels anyways. There's the concern of "Will the whole thing come out" I suppose, but from a AAA publisher/franchise, it seems doubtful they'd axe it midway through, whereas the indie studio might collapse in on itself more readily. I could see personal preference too though. Some folks just want to play a game in a solid sitting. Random 90 minute-2 hours, then wait a month or more for the next level is a bit of an odd plate to serve up. I'd actually find it more annoying if it was more story-driven like Telltale stuff, as if I'm engrossed in a story, I don't want to just jump off at some stupid cliffhanger point and/or forget elements of the story by the time the next bit rolls out.