It was still under their experiemental era. When they were interested in the Wiimote, EyeToy and Kinect.
... and handheld gamings. Sonic had games more on handhelds than console.
Steam was still starting and SEGA wouldn't put their games there until later in 2010.
And somehow SEGA's first games on Steam weren't Sonic but Golden Axe, Ecco the Dolphin, and Vectorman.

The rest of Mega Drive collection games followed later and then Sonic Adventure DX: Director's Cut launched in 2011.