It's not the score he gave it that bothers me - it's everything that he did that led up to the review, as well as the aftermath via his video response of his own review. It was completely unprofessional from start to finish and that's pre, during & post review.
No one else in the games media industry acted and reacted the way that he did regarding BOTW. He was trolling before he even shared his review, he trolled during it and then gave a lower-than-average score merely to fan the flames - only to post a video less than 24 hours later that he obviously had at-the-ready just to fuel his own agenda.
What is professional here? His website got DDoS'd and people were calling him names even before his review went up when he started expressing frustration about the durability. Are you saying he shouldn't have addressed it? Or are you saying he should have behaved differently with this incident then he does with any other industry problem he encounters?
He has a brand, and a brand personality. Part of this brand is being a consumer advocate with his harsh, voice-of-the-people rhetoric, even his outfit is inspired by such media imagery. Now, to you, harshly and playfully calling these groups out and unifying that message with his already stated misgivings about the systems is somehow unprofessional. But that's what he does, and it's not attention seeking (that is, any more than it necessarily is as a product he is selling, same as any review ever). He genuinely believes his views, and he goes through a damn lot of trouble to articulate why. His review was extremely thorough and expansive. But if he didn't deliver those views in his signature style, or he didn't go after those "babies" who are literally crying about the score for no reason... he wouldn't be delivering his product.
And people who pay for his product expect it. For you this is "seeking attention." For Jim, it is "delivering the product people pay for." He's a consumer advocate who is also delivering a product his consumers
demand. When you parse it out, you can easily separate what he does from true attention seeking. Because nobody seeking mere attention would put in half the effort he does to elaborate on the problems he has. There are far easier ways to troll fanboys, because fanboys are the world's easiest target.
Honestly, if someone else comes out of the woodwork with a 5/10 review - if I believed that their concerns were genuine and they handled it maturely and professionally without trolling or needless Nintendo and Zelda fan-bashing, then I would accept it as professional; but I really and truly think that Jim Sterling is only doing this to spite fans and because he doesn't like Nintendo.
By the standards of Deckard Chapel, he failed. But you have not proved by any measure that he has not described his problems at length or that he doesn't really feel this way or that he was wrong to get angry at the people who ridiculously overreacted over a score. You don't like that he called them out on it, or that he plays with them as a cat does a ball of yarn. But that is the product he delivers. His job is NOT to let those things go, because it's less entertaining if he does. And he's not just a critic - he's an entertainer.
And you are fine not to be entertained by it. But accusing him of being inauthentic in his views or intentionally giving it a low score to rile people up or some shit is just absurd and completely out of character for who we all know Jim is.