That's my point. Suggestions seem to be that the units were ready for use, but a specific group of drivers didn't want to drive them.
I get that, but what's to say that by moving them to a new TOC their drivers will be 'eager' to drive them? As far as I'm aware the main complaint is that they were a downgrade with worse cab ergonomics, so chances are unless they are replacing trains with an even worse cab they might still face issues. The issue was with ASLEF as well, who represent not just GWRs drivers. I get that this was eventually solved at GWR, but I feel the units themselves hold more of the problem.
If Porterbrook want to take revenue with them there's no particular reason why they need to go somewhere where their tri-mode abilities will be used. They're also simply DMUs or EMUs with brand new interiors.
But in that case they are a bit of a 'Jack of all trades master of none' scenario, which as far as trains go seems to be a lot worse than being a master of one! As EMUs go they are old and are worse in most aspects than almost any EMU class I can think of for both operators and passengers, bar perhaps units like the 455s which have clear replacements lined up anyway. The 379s are some of the best EMUs around and yet they still haven't found a new home, so I suppose it would all be determined by how much Porterbrook would want to charge in the unlikely event they even decided to try and find a new operator - a lot less than the 379s I would hope!
As far as being a DMU; with similar performance to something like a 150; why would an operator bother replacing a fleet of those which have been working fine for years with a train that is unproven and overly complex for it's job?