The title is a little misleading since they aren't hiring engineers off the street for $1 Million. You have to actually start an interesting company that they then acquire for $1 Million (even if they shut it down). It would be hard to justify hiring someone off of the jobs site for that much money.

Some insight into why - acquiring a company is considered a capital expenditure that comes out of a different account/budget than operations (salary). The cash balance at a lot of big companies is treasury so it's a lot easier for them to spend it on capital expenditures than on their employees.