@Steinzy Lurppis (A csgo analyst) tweeted this:
Also looking at it very basically, if I were Bliz, buying MLG would allow me to:
Make money from Dota and CS:GO, as well as more from Call of Duty and whatever else they run.
And have a proven platform to do my esports stuff. The world is very much becoming a "Why do something yourself if someone else can do it, just buy them" place.
For example, Google trying to do live streams of games, cant compete with twitch. Amazon want to do it, buy twitch.