It's definitely genre - but that's partly why the PCs are supposed to roll with it and get on with their lives (or more likely plot a long course of revenge), on the streets, working from job to job, and staying hungry for the next score, and, quite possibly, on the wrong side of the law. If the players aren't really agreeable with playing with that, then they may not be so simpatico with the genre. And that's fine. Not every genre of game is right for every group.
Nah.
@Doug McCrae is right. The issue is that the adventures in question expect you to keep going with a now-pointless mission, or work for someone offering you even less money, which is completely antithetical to the genre. The problem is the adventure design - RPG players are natural cyberpunks, in my experience. But quite a number of early Shadowrun adventures seemed to be written on the basis that the PCs were some sort of, well, suckers.
To be fair this did improve with later SR stuff. (EDIT: but see below)
What really highlights this as an SR/adventure issue, not a player issue is CP2020, where the same players didn't have any problems, because those adventures, when you got betrayed or whatever, the adventure actually accepted it, and accepted that you might ditch things then and there, or seek revenge, instead of merely seeking alternative backers.
This explains a lot! My only experience with Shadowrun has been at several GenCons. My friend and I sign up for 1 Shadowrun adventure per con, hoping against hope that "this time" it'll be good (the descriptions are always so great!) An they're just not - EVERY one has some kind of big betrayal that makes the rest o the adventure pointless.
The last one adventure were at (I'm going to name names - It was A Girl and her Dragon) at GenCon 2019 had that problem and it had the cardinal sin of half the characters being completely useless for the mission we were given (which is amazing given that characters were pregens - so the organizer/GM literally made characters that were useless for the adventure).
Oh wow, still happening in 2019 huh? Goddamn. And yeah that's exactly it - the betrayal renders the rest of the adventure
pointless - it's very different to the betrayals in cyberpunk books/movies/etc. - those tend to merely change the story, re-frame it, or whatever, but Shadowrun demands (literally, in at least one edition) that the players buy into this deal where Mr Johnson hires them to do something (rather than being more self-motivated cyberpunks, which admittedly would be harder on the GM, because SR is complex and doing stuff on the fly doesn't always work great), yet loads of the official adventures completely take a dump on that buy-in.
It's a really good illustration of how modules can be the problem actually, because a lot of the complaints here have been "Well players bought in to the premise, so they have to stick with it!", but these adventures just destroy their own premise, and not even really in a genre-appropriate "you knew the risks" kind of way which would allow for counter-betrayals and so on. One from the '90s even had a bit which basically instructed you to prevent the players from preparing for betrayal or engaging in counter-betrayals, basically with heinous railroading.