Inquisition wasn't rushed, it was cross-gen and mismanaged. They had to cut good, functioning content to accommodate the PS3 and 360. That content never should have been made. Had the game been properly managed that content would have been scrapped much, much earlier and more work would have been done to make the empty, boring maps more lively and engaging with actual sidequests.
Actually, I think one of the core issues with DA:I is that the initial design period (the ever important 6-12 months of game design, story planning, etc), and a lot of the actual development time coincided with the obsession the game industry had with 'open world'.
On the surface, if you look at the Dragon Age games, going 'open world' around the time it was being built seemed a logical progression. Further, the actual timeline for development coincided with many massively popular 'open world' games, where a lot of the games media was talking about how bad it was that narrative was 'linear' and at the same time praising the early open world games - basically saying "why cant every game be open world".
Of course, now that sentiment has flipped on its head, and games journalism has universally condemned open world in what is basically a 360 of their opinion. You could paraphrase it to something like, "Actually, open world is all good and well but go back to having good quality stories and not having an extra 20-40 hours of padding/filler content".
Recent really strong evidence of this marketing data is retiring the annual Assassins Creed franchise, (stated reasons being due to sales slumps and much complaint about padding). Also, regarding open world/sandbox game reception, I would generally call recent reviews 'polarized' with notable games like Mad Max and Dragon Age: Inquisition, as having mixed reviews citing reasons like too many fetch quests and MMO style padding.
Look at the 5 years Bioware has has, I really feel quite bad:
SW:TOR
1) They start developing an MMO when the MMO genre was at its peak, and by the end of the development lifecycle, SWTOR's core gameplay is outdated.
2) MMO's in general are on the decline. The core 'gameplay loop' with hotkey combat has been played out and simply doing a WOW clone wont serve.
3) The current MMO trend at the time was at least having "live action MMO", as something new.
4) The story driven MMO concept, which was the unique take from Bioware, did not seem to supercede gamers being general tired of the genre by the end of the 4-5 year development cycle.
DA:I
As mentioned above, sandbox/open world was very popular during initial development, largely tired by the time DA:I releases.
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I mean, this is some seriously bad luck, BUT, there is a light at the end of this dark tunnel. I think the consensus is that Bioware has been a leader, if not THE leader in story driven content for over a decade. Bioware arn't idiots, surely Bioware have leaders and employees that have learned from the experience of trying to capitalize on 'industry trends', rather than focusing on their own success and doing what they know best.
From many public statements about ME:A, it will not be a DA:I clone in a sci-fi setting, they are keeping much of the story-focus, semi linear/semi open-world nature that we know and loved about ME 1-3. This isnt certain, but from reading between the lines of their PR this is what i gather.
If i had to guess, I would say they will add a bit of exploration and open world, but keep it fairly tight so that the overall experience feels less padded with uninteresting content and is more satisfying. For instance, barren parts of the world with a focus on herb collection will be replaced with optional planets and sleek/interesting driving with occasional rich and interesting rewards.
Also, the setting of their exploration being 'new worlds/planets', and driving a futuristic space vehicle is fairly advantageous over herb collection in terms of being interesting... just putting that out there. One would be a 9/10, the other a 2/10 on my interest level. Had the Mako in ME1 had the variety in worlds and customisation options being touted for ME:A, I think it would have been a much better received open world feature.
And this bodes well for ME:A. I think ME:A will probably have a similar marketing campaign to The Witcher 3, it will have a kickarse story, and it will captivate a large portion of the 'mum and dad' gamers, even more than ME3 did. I am betting on it being the most successful Bioware game ever - due to learning 2 extremely important lessons in the past 5 years.
Dont get me wrong, there will be hordes upon hordes of obsessed haters claiming they will never buy ME:A because of what Bioware did to ME3, but put simply, a good game is a good game. Ultimately, if the game is awesome, it will sell to core gamers AND penetrate a huge portion of casual gamers and be a massive hit, just like The Witcher 3 did.