Google's mission:

"organize the world's information" - what information is being organized?

"and make it universally accessible" - are they going to make the building universally accessible?

"and useful" - I'm sure the building is useful without Google owning it :)

Google's mission:

"organize the world's information" - what information is being organized?

"and make it universally accessible" - are they going to make the paperclips universally accessible?

"and useful" - I'm sure paperclips are useful without Google owning them :)

Google really shouldn’t ever buy paperclips and the ones they bought in the past were clearly wrongheaded investments.

Also want to add to the original comment that google does have a lot of cash and my understanding is that they hire anyone who meets their high standards. So what is the downside to stepping outside of their core competencies and buying real estate? Put another way ... what else are they going to do with that money?

Actually, Google's core competency is selling targeted ads so they need to be wherever people's eyeballs are. So branching into email, mobile, etc. is actually a natural evolution.