I think the truth is Google is just like any other large company. It's priority is profit, but it's learnt that sometimes the positive effects of giving away certain pieces of software (gains them "coolness") over weighs the downside of them keeping things closed source.
Google are masters of this, they developed Andriod, whilst many hail as awesome because they gave it away. The truth is this is no more than a gimmick to them, like chrome. Google still make their money via advertising on their search engine, the code for which of course they keep closed source.
Google giving offering free services like Google Earth is akin to Shell giving away a free model car every with a few vouchers. It's pathetic. We buy it, we think Google are different, they're pro us. They're not, they're a money making company that couldn't give a rats bottom about you, me or the open source movement.