No, I don't think that the value systems can be ignored, I'm saying that ability to implement might be more important.
For instance, suppose you highly value environmentalism, but the party which puts environmentalism as their #1 option wants to stop nuclear power (as is typical of environmentalists). If you believe that nuclear power is the best clean, reliable option we have the technology for now, then you might vote for a party which has environmentalism lower down the list of priorities (and no-one wants the environment to be polluted) but has greater expertise.
I'm saying that ability to implement might be more important.
Depends on the degree of mismatch we are talking about, but generally speaking, no, I still think that similar values are MUCH more important than the capability to execute.
Your example, by the way, is not about expertise, it's about the value mismatch (you highly value nuclear power and the Green party highly disvalues it).
I just saw that Donald Trump is running for president. Which led me to the following thought: would any of the big names in tech have a chance at being elected president of the US? Elon Musk? Sergey Brin? Jeff Bezos? Reid Hoffman? Peter Thiel? Edit: Bill Gates?
Some follow up questions/thoughts:
Edit: hypothetically, if one of these big-name tech people were to try to gain political power, how should they go about doing so?