Ryudo on 09 March 2009
I can't speak for this gen but last gen it mainly started because Shiggy was good friends with Yuji Naka and others at Sega and being formal rivals and a attractive platform for the demographic of Sonic it made perfect sense.
Started out as a combo of things.
These days I honestly can't say beyond the obvious for sonic but HOTD and other mature titles but I am just glad they are.
