The difference here is that GOP right now is very very far into the right, there are very few in the GOP party that are more in the middle, like Romney or Cheney. It's very hard to say vote for the GOP and claim to be a centralist in the current climate.
Therefore, when Elon asks people to vote for the GOP in the current climate, they are voting for this far-right version of the Republican party. Your argument would hold more weight a few presidents ago. It's very hard to see him as a Centralist for me, and some people.
p.s. what does it matter what i think which way he lean? Why are the Elon fans so eager to defend him at every step? That is the most strange part to me.
Could you tell us which of their views are "very very far" into the right?