Games exist at the intersection of art and software, and when things go wrong technology makes for a convenient scapegoat. I don't think Amy Hennig is doing that here but the way it's been reported erases a lot of the nuance.
This so very much.
The technology may be a single reason (among hundreds of additional, compounding reasons) why we never saw much footage or why for creative it may have been a difficult project as much of the work is waiting until the team can get to the real iterative gameplay work, but I don't think Amy is necessarily portraying it as a reason why the project failed, more as in just one of the challenges of building that particular game.
Remember, she even specifically mentioned the project was doing "fine":
And look, I mean all I can say is the project was going along fine.
...
I wish people could have seen more of it because it was a lot farther along than people ever got a glimpse of. And it was good, you know? But it just didn't make sense in EA's business plan, ultimately.
The engine may have been reason why the game would have taken longer to build than if they had another engine to choose from (but that may for example have resulted in worse performance), but in no way does she explicitly mention that it was a reason why the project failed. Just that it was one specific challenge, and one the she may or may not have expected coming from a different studio.
If you read between the lines the problem is that their team simply didn't have the technical expertise to dig down in system programming.
That's not really correct either, as she specifically mentions that they did end building those systems and that it was work that would eventually benefit other teams. Not to mention Visceral certainly had engine-level programmers in their studio and had previously worked with their own internal engines. In fact, it's quite frustrating to always hear that people assume issue have to be because of lack of expertise/skill in a given studio, because the reality is so different, but people just like to assume the worst of other people they do not know.
The more accurate issue is, that it puts a massive strain on the creative design part as you can't really iterate on systems you can't play, so you are left theorycrafting and waiting for those tools to built, before you can actually start iterating top-notch gameplay. Gameplay design doesn't live on papers, it's really about getting things playable and iterating them and when you are waiting for tools for that to be possible, it can be frustrating. And often studios can't wait for the time for these tools to be built before moving all of the production staff into their project, these issues are/were quite common before some publishers like Ubisoft have adopted a more scalable way of handling staff between projects and ensuring lengthy pre-production times with a small team.
