Our guild is highly active, and almost without exception share the ten wins amongst all our members. It gets frustrating challenging guilds that have 3 or 4 active sides (who are crap anyway) and the rest don't even front up. It's especially misleading when they claim to be decent, like including New Zealand in their guild name.

I think anyone who plays less than ten games in a losing gvg should get marked with a badge to warn people, like maybe vertical bars of blue white and red, so we know they'll just roll over at the start.

That system is already in beta, I believe. I've seen the badge you describe, and although there is the odd exception, it does indeed flag those guilds who roll over in guild challenges with minimal participation. I'm unsure as to who has been making the guilds adopt that colour scheme, though.