Well, now it is my time of throwing in my 5 cents ( sorry, dont have any smaller change):
We should maybe try to see both sides of the question... Arduino is, for a vast majority just a nice way of interesting younger people into programming, associated with the natural instinct of of building things and pulling them apart. And has been quite successful at that. hence the wide success of shields, where it avoids that learning curve of the electronics side of things.
There is also quite serious projects and people using it, and to good effect at that, so covers both ends of the spectrum to be honest.
So, if Fritzing does shorten the learning curve for many that dont really have an interest to deepen their knowledge on the electronics side of things more than they have, so be it. Myself can proclaim to be guilty of using it to build a PCB file to be sent to a pressing company on gerber format( but you neither would want to see the schematic tab nor the breadboard as its a ratsnest: and no-im not talking about the line lol).
So, attacking an open source program like Fritzing just for the sake of purist pride is not the way to go.
I know how valuable a schematic is, but for someone coming afresh into the world of electronics, just the immense specs and different values of components is enough to scare them away from the start ( lets give a capacitor as an example where just for basics you have polarized or not, value, voltage limit AT LEAST...This if its an electrolytic! if its a ceramic, etc you will also need to know the codes for the values!!!).
So, dont see nowt wrong with being practical, if that is easier...even if just for a while !!
Anyway- everyone is entitled to their opinion.