Again, I've given games 10/10 despite performance issues. It really depends on overall experience for me. Perhaps I'm not as clinical or calculated as the press. Dark Souls was easily a 10/10. Other games like Mass Effect could've easily been a 10/10 if not for some redundancies in side missions (despite shortcomings in side missions). I'm pretty sure Read Dead Redemption, a game which I achieved "satisfactory completion" on recently, also got close to that 10/10 mark ('d probably give it a 9/10 if not for a few niggling things).
BotW being a hyped Nintendo game predisposes it to high praise but I think when people are blown away with games, they're just blown away, period. Even with flaws, I see no reason why games should not get 10/10 when they are absolutely enthralling to the player in all the right areas. Yes, Nintendo games have an advantage due to pedigree, but the tentpole games usually end up indisputably incredible due to Nintendo's attention to detail.
Anyway, I picked up my in-store purchase at Best Buy today. I let my roommate play the game for the night since I wanted to finish some things in RDR (and he'll have his copy in the mail this weekend, likely, so I figured I'd just give him a preview by using my copy first), but once I start Breath of the Wild myself I'm willing to put aside performance issues, just as I did with Dark Souls, so I can appreciate what could potentially be the best game of the year. I'm hoping BotW lives up to my expectations, even if I'm playing the partially-compromised Wii U version.