The Grinder (73)
Quantico (70)
Blindspot (65)
Life in Pieces (64)
Grandfathered (63)
The Muppets (62)
Scream Queens (59)
Code Black (57)
Limitless (57)
Heroes Reborn (53)
Minority Report (51)
Blood & Oil (49)
The Player (43)
Rosewood (37)
Dr. Ken (28)
Average rating of renewed shows: 54
Average rating of canceled shows: 56
So, it looks like there is no correlation, in fact canceled shows were liked slightly more than renewed shows by critics. This gave me another question: what if we removed renewed shows with good timeslots (Blindspot, Life in Pieces, Rosewood), and canceled shows with bad timeslots (Grandfathered, The Grinder, Heroes Reborn, The Player, Blood & Oil)?
Average rating of renewed shows with a solid chance to fail: 54
Average rating of canceled shows with a solid chance to succeed: 57
Nothing changes! Well, some may consider The Muppets to have had a bad timeslot, considering that it aired at 8:00 on a troubled night for ABC. That would bring the canceled average down to 54, the same as the renewed shows.
So, in conclusion, being "good" or "bad" doesn't seem to mean anything when it comes to renewals and cancelations. We all expected Dr. Ken to fail, but it succeeded. Could this be good news for shows like MacGyver this fall, whose trailer was hated?