Which, yeah, I can see how it would get annoying, particularly to his Senate colleagues but also just to Republican voters. Not even so much the positions themselves, but the attention and positive press he always gets for being so brave and taking a different position from most of his colleagues. Though it doesn't happen remotely often enough to make him a RINO - on most topics, his ratings and vote record are quite conservative, not like real centrists such as Collins (or, on many though not all topics, Murkowski).
But press fawning or not, it's certainly a good thing in these hyperpartisan times in which most Congressional races have become about voting D or R with barely any regard for the candidates in question, that some people still can build a reputation on defying the party line if they think it makes sense to do so.
And no, I don't always like his aggressive foreign policy positions either.