Clint, unless you know very well the sound of every component in my system and the room it's in I'm not sure you can judge it as a system issue. If you look at my voting record you will see that I tend vote on the lower end of things because I think something has to be really, really good to merit a ten. I have a wide spectrum of scores (from 2 to 10 IIRC), but there appear to be people who vote high up a lot of the time - where's the objectivity in that? That seems to be a "I really love surround sound, and this release is in surround sound!" or "I love this band: everything they do is a ten!" which is perhaps to be expected in a hobby site but is not necessarily helpful either. I don't follow the content/fidelity/mix guidelines (I don't think this is new news) and they are only guidelines rather than rules, and I attempt to justify my scores in all cases.
I also don't subscribe to worshipping the work of an engineer/band and decreeing they can do no wrong (I'm not saying that you do, BTW). If everything was like five and below then I think it could be put down to a system issue or perhaps even not liking surround sound, but it's not, so I think that gives plenty of scope for taste and an attempt to give some proportion between releases. I'm not ruling out system dependence being a bigger deal for some mixes, but someone posted an article on different engineers approaches to 5.1 and if the engineers don't all agree then surely the listeners won't either? And yes, I'm not above questioning other people's votes as you have spotted - even (especially?) high ones!
In other news, it appears that I'm not currently on your ignore list!