I wouldn't call it a rigid standard by any means. I think of it more like common sense. I'm not accounting for those that are typically more paranoid than most.
Nothing about security is absolute; it's all about risk management. Sure the impacts are huge here, but what are the likelihoods? When protecting yourself (digitally or physically), everyone takes a reasonable approach and draws the line on what is acceptable to them. In this specific case, if your second factor is compromised, your first factor is still intact because it's different for each resource. If you use strong keys for your first factor, then you would have to be specifically targeted for both factors to be compromised. Unless you're someone really important, the likelihood of that happening is next to zero.