With all of Google's bandwidth you have to ask why did they limit access to the maps API? I have to imagine that they got what they wanted, so many people used and shared information on that service that Google got to where they figured "we have enough info now, why waste resources supporting free users and leeches?". Who knows.
To be fair, at least Google is allowing you to use $200/month free still -- WUnderground is flat out pulling the rug out from under everyone. I'll probably create a billing account on Google using one of those stupid pre-paid Visa cards that I get from "mail-in" rebates. That way I really just can't be charged even if I have a billing account. I wish I could do the same with WUnderground...
I have to point out that the open source model, where lots of people contribute often times for the benefit of their business but also for other's benefit as well, is free and a lot of it is quite good. Data may be different (thought there are also open source data licenses and sources), but as a blanket statement it's not really true.
I love Open Source and often you are indeed correct, but I
generally find the commercial alternatives are better -- at least for the tools I use. I sometimes still see the Open Source option as a better value in that I don't care about the extra features/stability/whatever, but in my (admittedly small) area of use, the commercial apps usually win. (And before anyone jumps at me, I DO know there are times and options out there where OS is better. I'm just speaking of my particular generality/experience...)