I see this a lot. As for being "chemically bonded" to smc, that might be because there was some estimable player once who said, "smc is worth more than all the targets in the game put together." And while it's worth more than ANY other target, it's not worth more than all of them together. And that sentence has continued to live in many Guild Founders' minds, which results in an inflated perceived value to taking SMC. And it's true that SMC, in terms of position and influence, is a high-value target. But it's not worth that much. I've been on teams that deliberately sacrificed it so they could take the owner's keep. Keep, two towers, and a camp, together, are worth more than SMC alone. Chances are, with the lower population caps in WvW, the team cannot defend both their keep and SMC at the same time.
And it's harder still when there are just three of you on homebl, instead of six. Not sure what can be done about this. Maybe make the borderland targets worth more? Or give some other bonus? What if having all three keeps in a bl provided the entire team, including EBG, a boon? Say "heals 75 points a second," or some other plus? What if the level of the boon depended on the level of the keeps? What if each thing taken was worth something in terms of general support, and the level depended on the level of that claim? What if taking the last two claims didn't add to that? Gotta give the enemy a toehold, right? Else it's no fun at all for them.
Idk. Just throwing out some ideas. If some of them stick on the devs' walls, great. If not, oh well.