You know I like that, it pretty close to how I view things. Your point on eight almost mirrors what I feel about all might eight out of tens, very good but room for improvement but still something I'd easily recommend. Not sure how I rank 7, I don't necessarily see 7 as mindless entertainment because I put the original EVA series as a seven and that show isn't mindless.
I think for how I define a 7 is that the show is lacking something, that might be direction, pacing. But it still a good show. 5 is my average, so 6 is above average and 4 below average. I try to steer clear of anime that more likely going to irk me into throwing it down into 5 territory. As a result the bottom of my list and how I define 'bad anime' is pretty hard. I suppose it going on instinct - I hated MD Geist and gave that a 3, but Kokoro Connect was somthing I couldn't even sit threw so easy 2.
As for my top scores, I don't really worry if something needs to be accessible to newbies or the elites holy grail on Anime it just, if I consider it a masterpiece and constantly find myself reflecting on the show its got to be a 10 out of 10. I often see my 10 out of 10s there for as very subjective and they could easily find themselves as 9 or 8's in someone else's list.
For example my top show Monster isn't something I'm gonna recommend a newbie who might have only watched Pokémon because that just impossible to expect. But it's still a masterpiece in my opinion.
Just checked you're anime list out and trust me, you got to give Stein's Gate another chance. Currently sitting on three episodes and believe me that show get good. Really good.
Also I'll repost my anime list, cause it probably buried somewhere in this thread and I haven't link it to my posts because I have no idea how
AnimePedestrian's Anime List - MyAnimeList.net