^No, it's the most sensible approach which is the least inconvenient for the majority. It's okay to click on the image if you want, just don't read the comments? Don't tell me that's impossible. The pairing is written on top.
Your "common sense" is actually just your preference. Many forums do apply this rule because it's a bother to listen to people's complaints, not because it makes the most sense. Please, just think about this: Why are you reading comments on a series you don't know? Do you lose anything by not doing it? If you don't, then you have no reason to do it. If you still do it, you wilfully expose yourself to something you don't know. In that case the only thing that matters is whether you care about spoilers or not. If you do, you made a mistake. You are asking the majority to bend for a few odd cases who want to look at something they don't need to. You're asking people who naturally discuss what they came for, to add spoiler tags for pretty much anything, as a spoiler is so ill defined.
Ahem... This is just a matter of principal. You did reply to me though, so that's why I responded... Sorry if that seemed pointless to you. ^^;