I think you would have a hard time in any airline avoiding disciplinary action if you refused to take an aircraft that was signed out as legal to fly.
I don't see why. Somewhere in the preamble of the MEL that affects my operation there's a comment, for example, that the PIC must assess the implications of multiple MEL, and other operating conditions.
I recall an incident many years ago under Mr Smith's Class E from FL245 to A045 (or similar) where an F/O left an aeroplane because "expediency" approved flight with a u/s TCAS, rather than fix it. That captain's position on the day was, "it can be MELd so I can't say no." This thought process overrode the Ops Manual that required repair in a location that repairs could be made, and the warning preamble.
The F/O in my opinion made the correct decision and whist asked to explain their actions there was no disciplinary action.
An impartial observer may have said that the original approval to operate was designed solely to avoid a delay.