They aren't designed to allow you to see...they are designed to allow you to be seen. Hence why they're redundant, because if you want to be seen, you just stick you headlights on. If they were actually useful, then they'd probably be compulsory on all cars...you know, like rear fog lights, which are actually useful.
That said, I've stopped getting annoyed at people using them "unnecessarily". I used to get irritated about it, until I stepped back and looked at it objectively and realised that actually they rarely bother me at all. I was only getting irritated because I spent too much time on the internet listening to others moan about them.
Put it this way, I'd take people driving around with front foglights on all the time, over people not using foglights (or any lights) when it actually is foggy. I find the latter much more concerning.