Honestly I just find the plot fundamentally unbelievable. You're telling me someone who can whip up an intelligent, human-passing synthetic with full sapience couldn't get funding from corps? Techbro investors would be dumping money on her faster than you can say "cheap labor." And that's not even getting into the idea that someone smart enough to make a sapient robot would go "oh you're just a robot, let me edit your mind now that you're obsolete."
Just incredibly contrived for the sake of the "disturbing" ending.
Honestly you kind of have to have a thick skin, when it comes to things like, plot holes, continuity errors, and flawed and sometimes inexplicable character development, in modern popular media.
My friends and I constantly bicker about movies, because I've disregarded obvious flaws, that ruined the experience for them.
For example, I too thuoght it was B.S. that someone that skilled, in robotics wouldn't be able write her own ticket, but then I shrugged and thought well whatever.
I also thought if Kei-san thought that Marie was just a robot running a program, to simulate love, why did she even bother with her little "breakup speech". She could have shut Marie down for maintenance and removed the "love code" with no fuss or muss.