Yes, as that is possible to happen, it's also a fact that most players aren't in full greens or blues. Yes, there are some, but it also means that green players don't ALWAYS get with green/blue geared. My Druid is just on the road for Full pride and there are times I have the highest HP on my team except for maybe a Warlock/DK. The suggestion, as much as it's a double edged sword, it also adds in more fun, more competitiveness, and makes the BG more random; Friends pinned against friends, guildies vs guildies, and so on.
Also; I was just throwing out the idea, if it's easily possible or not let alone even doable, I don't know. I know for a fact that I saw a 3.3.5a server that shall not be named(As well as if I have the right server in mind or if it's still up or not is beyond me.) that did this, and just thought it may be a good idea to throw out the idea and get feedback and maybe be implemented.
And yes, it is the fault it's the Alliances fault they lose so much; And there are times I play Horde and I want to throw my keyboard across my room in how terrible we do, but there was only once that I felt more rage than when I play Alliance. Aside from that fact, the suggestion was just an idea for more fun as well as way to fix some minor problems amongst the factions and faction ratio's.