The answer seems simple enough - Google wouldn't want to be saddled with NAVTEQ's customers and history and infrastructure. It's not just about the data, NAVTEQ was a business in and of it's own right. Nokia buying NAVTEQ means they now have a direct line to sell both data and electronics devices to these customers. Not something Google would be interested in. But how does Google deal with increased pricing or even lock-out from data providers in the future?
What people are really asking is "Why didn't Google buy a data company?" But they have. At least, they're investing in data. Google is 'crowdsourcing' in India (though seems more like 'outsourcing' with a prettier moniker). They're also paying users everywhere to map businesses. This gets Google what they want in the end -- data.
Ed Parsons says it fairly plainly:
what will be interesting in the future will be the relative contribution made by 'Cloud' collected data
OpenStreetMap providers 100%, free, verified coverage in the Netherlands. Imagine that, there is now little to no reason to buy raw data in the Netherlands anymore. Value now comes from building great services on top of that data. Now carry forward a year or two when OSM has coverage of the other countries in Europe, Asia, and the Americas. Google/Yahoo/Microsoft win - they have all the data they want and can then bundle this into their web services, mobile devices, etc. without having to track usages, licenses, or derivative works. Everyone wins.
My only concern is their past history in leveraging this data out of the institution but keeping it privately inside Google - only released under approved TOS and API's. Hopefully in the future they'll release this data - at least in it's original form - back to the public.
And there still is a market for NOKTEQ or Tele/Tomlas - or even newcomers like CloudMade that will take all this free and available data, package it, verify it, and deliver it to customers that value things like SLA's.