The rule mandating low noses came about because the FIA was concerned that, in the event of a side impact, a car could penetrate the safety cell of another. Those concerns were not unfounded; Michael Schumacher spun on the opening lap of the 2011 Abu Dhabi Grand Prix and nearly got a face full of Force India when he was hit by Tonio Liuzzi.
The finger noses came about for two reasons: first, the teams are unwilling to sacrifice the benefits of a high chassis. If they can get more air under the front of the car, they can pass it over the splitter and into the sidepods, creating more downforce and more cooling. Secondly, the rules themselves were written in such a way that the nose only required a minimum cross-section, which inadvertently led to the creation of finger noses. Some people will accuse the FIA of a lack of forethought, but the truth is that this is an outcome that was not considered when the rules were written because it never occurred to the authors. In hindsight, it was something that they could have seen coming, but these regulations were first published in August 2011. And every time a rule is written or re-written, loopholes naturally come about. People get outraged when the FIA amends the rulebook midseason, but they only do it because they have to - because the teams found a loophole and the FIA was only made aware of it because someone exploited it.
Personally, I think the teams haven't got a leg to stand on when they complain that their cars are ugly. They had the ability to design a good-looking car, but prioritised performance first, even if performance came at the expense of aesthetics. To then complain that the cars are ugly is a case of trying to have their cake and eat it, too.