Google may only have 57k engineers, but jobs that benefit directly or indirectly from Google is huge, such as companies who partners" with Google, or sells to them, this goes straight down to the restaurants that eventually pops open within a 5 mile radius to feed the engineers...
Another example is if you had a $1 bill, and went to spend it, that $1 dollar doesn't stop and disappear at the store you spent it at. It could go into the pocket of the store owner, who then would take it to spend somewhere else, then the next person would do the same, etc..
Something to consider here, Tech jobs provided to engineers are high paying jobs, quality work that enables them to splurge: buy a nice house, with top of the line furniture, maybe remodeling or renovation, take some vacations, etc.
Arguably the computer was meant to replace a lot of jobs, but it actuallity, it created more. The SMP2 only shifts the market towards higher demand for engineers, designeers..students will pursue this field as long as there is demand for it. Kids today are more tech savvy than any generations before (gee I wonder why?) Those who aren't "smart" enough to enter this field can benefit indirectly, as stated above..