It's my opinion, ok this one is your.
Small portion of the game? It was no small for me, it's two true chapters. For in game chapter 7, the last dungeon is perhaps not very well filled, but huge anyway and with 3 big and difficult puzzles and some other tricks to manage. Before that not only there's a fair amount of stuff, but also you have a lot of time to play more stuff, as to achieve the Lieche quest, or the dark queen quest, or eventually finish some companions quests you failed finish in previous chapter.
Ok chapter 8 is perhaps smaller, but no magic during a quite long part, sorry but it's an insane design.
Mass of players never ever forgive Bioware for ME3 ending, it's hugely worse for PK. And if they deeply fix all this crap design, myself I'll forgive them, Bioware fixed it for nothing, most haters ignored the fixing efforts forever.
For me ME3 ending was a detail, just few minutes and I was enjoying the unexplained aspects keeping some mystery, and the heroes death concluding perfectly an epic and heroic destiny.
In PK it's not some minutes, it's 20H of boredom play to finish this game. I can't forgive that, but ok Im' sad that Biowere get bashed so hard for ME3 ending, so I can imagine you have a sort of similar point of view for PK.