It's always frustrating when a game seems to have had a turbulent development cycle and it seems like we'll never know exactly what went wrong.
Mass Effect Andromeda ranges is people's views from pretty terrible to good but not up to Bioware standards. Even among those friends of mine who liked the game, I've yet to hear anyone disagree that it's the worst game in the series.
Of course it's dissapointing. Mass Effect is my favourite series yet I've actually given up on finishing Andromeda. I only had a few missions to go but there was just nothing keeping me there, and so many other great games to play this year.
But for a lot of people, that dissapointment turns to anger, and rather than trying to be constructive we tend to focus on questions like "Who's fault was this?!" and "Who needs to be punished and how severely?!"
With the recent news that Bioware Montreal has been downsized to a support studio for the other Bioware branches and that the Mass Effect franchise has been put on hiatus, a lot of people gleefully hear this as basically the Montreal team being punished, which having what limited information we do is probably an exaggeration.

A few things to keep in mind about the goings on at Bioware over the last couple of years.
> Bioware Montreal is being turned BACK into a support studio. Before Andromeda, the Montreal team helped out the other Bioware branches and worked on DLC, and that's the state they are being returned to, with many of the current Montreal staff being funneled into other EA development houses.
> Bioware Edmonton is currently hard at work on a new IP and has been for several years, while Bioware Austin has been working on Star Wars games including currently a new Knights of the Old Republic. So both the full development branches are very busy.

With both of those things in mind, I think the more likely scenario is this: After Mass Effect 3 and Dragon Age: Inquisition, both Bioware dev studios would have their hands full for a while. If we were to get another Mass Effect game, we would have to wait until they the time and interest in continuing with the series.
So with Bioware having more popular IP than they have time and recources to actually work on them all concurrently, publisher EA looks over at support team Bioware Montreal and thinks to itself "Hm. What if we threw some more people at the Montreal team and let them have a crack at a Mass Effect game?"
The hope probably being - for both the publisher and the team newly upgraded to a full development studio - that they'd end up with a third Bioware powerhouse thus enabling three IPs to be worked on simultaneously, not just two.
But of course, that was not to be. We have only buts and pieces of information, but rumors and whistle blowers have come out i the last month or so that development at Montreal was very troubled. Important people leaving the project, degrading working conditions, unreliable outsourcing, etc. We will never know what of the game's short comings can be attributed to unskilled development or poor management, but from the sound of things, this development cycle was never going to have a happy ending. Which sucks.
So the publisher's little experiment failed, the conclusion being that (for whatever reasons we can't be sure of) the Montreal team can't handle full development, and are now returning to their previous state as a support studio. Andromeda was, if you will, their test, to see if they would be made into Bioware's third mighty dev team! Without wishing to sound harsh, it seems in the eyes of the publisher at least, they failed that test. Do keep in mind, game publishers are not known for their reasonable expectations, so... yeah. We can argue until we're blue in the face whether or not it was the right call.

So we shouldn't freak out. Mass Effect hasn't been canned or anything, and rather than it having been put on ice, that happened after Mass Effect 3, and Andromeda was it briefly being taken back out of the freezer to see if there was room for it in the dev schedule what with this new Montreal Studio, before concluding "Sorry Mass Effect, we don't have anyone to develop you at the moment, you'll just have to wait." and putting it back into storage.

I do feel really bad for the devs though. It's easy to forget what an astronomical task making a game often is, and management unintentionally sabotaging the devlopment of a game is nothing new. And sure, I think a lot of Andromeda's problems, like the writing, stemmed from some people in the team just not being skilled enough to handle an IP with this kind of pedigree, and the result of hiring a whole bunch of fans of the series to bulk up team numbers resulted in a game that felt less like a propper successor and more like a fan project.
But I get the niggling feeling that they were asked to prove themselves for the promise of being the new Mass Effect developer but were expected to do so with an unreasonable lack of wiggle room.

I feel like EA was just trying their luck. Seeing if somebody they already had lying around could be the one to keep pumping out Mass Effect games. And I think it could have worked. But it didn't. So with that in mind, giving Mass Effect a break and considering their next move carefully might be best.
And it sucks that a team of young hopeful devs weren't able to keep the leese on their shiny new position in the company.

ps. Why the HELL was ME2's planet scanning back?! We gamers are a pretty contentious bunch; there's not a lot we agree on unanimously, but that we never wanted to see planet scanning again is one of them! There's not a player under the fucking sun who was happy to see planet scanning make a come back! Who the hell made that call?! I want names! Give me names!