Extending the metaphor, the electrician has a long record of saying demonstrably untrue things about both water, electricity, and plumbing.
And the idea that alternatives look worse is just more stupid denialism, the idea that literally all alternatives are worse than someone who poops on all the furniture is just non-credible nonsense and begs for ridicule because it is that ridiculous. It's not rational.
...by not being a plumber?
However, if the main differentiating factor of your favorite candidate is that he had zero experience in politics, it's hard to take that argument seriously.
People considered Bernie Sanders an outsider, and he's been a senator since 2007. Trump isn't an "outsider": he's simply unqualified.
That is the sole datapoint a thinking, rational, ethical person needed to know to properly character assess Trump. If you still voted for him, you either liked that sort of blatant Nixon southern strategy 2.0 type of bigotry; or you're dismissive of it as a problematic attribute in a leader for this country.
And sure, Clinton necessarily must have been a fundamentally flawed candidate, hindsight being 20/20, to lose to that. But I put more blame on Democratic and Republican parties for sabotaging the Electoral College with party loyalists. Dead people would have done a better job, randomly selected people likely would have too, and contemplative people even more reliable. The two parties get way more blame from me for this setup to failure, than the people I think are deeply ignorant people in some form of denial for having voted for the Celebrity Chaos Clown.
Ok, but neither of those are irrational, they are judgements based around premises that are different than yours. You can argue whether those premises are rational, or ill informed or whatever, but then you're basically just wading into the usual swamp of political discourse - these issues haven't been definitively resolved and just dismissing the whole stance out of hand by calling it irrational doesn't get you anywhere. You're effectively just venting.