Very true. And saying MS can't possibly mess up since they ARE an OS vendor after the well publicized issues they've had recently with say...Vista...Windows 8, Windows Phone OS's until maybe the most recent (and I'd think the Mobile OS segment would be closely related to the console OS space), isn't exactly closing the subject with confidence.
MS has messed up plenty of operating systems during their time. The XB1 OS setup IS highly complex. Probably one of the only saving graces they have this time around is that their OS setup will have to deal with only ONE, set hardware standard. So they're getting to do an OS like Apple does as far as targets and controlling the hardware completely.
That being said, I'm sure both consoles are going to have SOME nagging bugs and missing features for the first few months. That doesn't mean that getting one day one is "stupid." You'll still be able to play some fantastic games. It's just that there will be some things that need to be fixed and added. This happens with just about every complex OS/hardware system that gets released these days and doesn't necessarily mean that one company or the other simply wasn't ready for the launch. Although..MS does seem genuinely disorganized this time. Still, that could just be poor planning and organization, not the result of having to RUSH anything. Look at Sony as well- they planned for this, seemingly fairly well too, but there's still a day 1 patch coming to put some features in. It's just the realities of product release in this day and age.