I'm not sure I understand your line of thinking, OP.
Do you believe Multibit's authors purposely inserted bugs in the software to prevent users from accessing their own wallets?

I discovered Multibit last year only and I'm curious since I've been researching various approaches to help a friend recover his BTC from Multibit 0.5.18.

I ended up succeeding using scripts to bypass Multibit altogether.
Personally, I don't know if Multibit author's intentions were malicious or not.
What I know is this:
- the BTC were still in the wallet and there had been no transaction since the 3 original ones from 2014 and 2015. If their goal was to steal, they didn't succeed.
- my friend told me that the password I discovered was based on one of his old personal passwords
- BUT the working password had some unreadable unicode characters in it, the kind he wouldn't even know how to type on a keyboard (would require ALT+[XYZ] to generate on Windows)
- when I tried pasting the working password inside Multibit's UI input field (including the unicode characters), as a regular user would to export the private keys, I still got this message:


Not sure I'm being clear, here's a screenshot:
https://imgur.com/a/4E3rDZY

So at the moment, I do believe Multibit 0.5.18 stores user passwords in a flawed way, preventing users to access their wallet even with the correct password.

You're not in this boat alone. I hope it helps you move on or try a new approach.

Good luck.