Uh... cause they would make cyclists feel safer and the city council & taxpayers feel like they're doing something to make their city more "cycle-friendly?"

You've hit directly upon the head about what's wrong with bike lanes - not that they are necessarily less safe (I'm not interested in starting that debate) but that advocates and everyday folks believe that they necessarily make cyclists safer at all times. If you think about it, of course bike lanes don't make cyclists safer at intersections... but at this point, everyone has drunk the bike lane Kool-aid. If there are bike lanes, it must be safer, right?? Because they're bike lanes! Lanes for bikes! This is taken as being so self-evident that there's really not much critical thought about why it could be true... and why it actually isn't. So ask virtually anyone, cyclist or motorist, what could be done to enhance cycling safety and use in their municipality, and 90% of the time they will say "more bike lanes." No matter how many there already are. So how come there never seems to be a point where people say, "hey, I feel safe now, no need for more bike lanes?" Hmmmm.