When you're Google's size the normal rules don't always apply, but I would say that generally any "non-core" investments should at least have some strategic purpose.
McDonald's for example, owns or leases huge amounts of real-estate, which they sublease to their franchisees. One reason for this is to maintain control over the franchisees. A franchise owner can't decide to close up and open a Burger King instead, because McDonald's would cancel his lease on the property.
I'm not sure how owning real-estate relates to what Google does. They are not a retailer so the physical location of their offices is not critical. Even if a particular opportunity is a "good deal" it's still a distraction from their core business. Even if management and maintenance is subbed out, somebody in Google has to keep an eye on things to some degree.
McDonald's for example, owns or leases huge amounts of real-estate, which they sublease to their franchisees. One reason for this is to maintain control over the franchisees. A franchise owner can't decide to close up and open a Burger King instead, because McDonald's would cancel his lease on the property.
I'm not sure how owning real-estate relates to what Google does. They are not a retailer so the physical location of their offices is not critical. Even if a particular opportunity is a "good deal" it's still a distraction from their core business. Even if management and maintenance is subbed out, somebody in Google has to keep an eye on things to some degree.