Democrats sure picked a great year to mess up. Had Democrats had a decent year in 2010, they could have made it so the only states Republicans controlled were Tennessee, Utah, and Texas while Democrats controlled New York, Illinois, Arkansas, Maryland, Wisconsin, Minnesota, North Carolina, and maybe even Virginia, and Michigan. Obama really screwed the Democrats at the worst possible time.
Ohio would have been interesting at best for the Democrats because after drawing a VRA seat in Cleveland it's virtually impossible to get more than 3-4 other seats that are reliably Democratic. The state is naturally gerrymandered for the Republicans. I've tried to draw a Democratic gerrymander a couple times and it's really hard.
If Democrats had a say in the map, the 1st district would have been kept competitive and the vote sink in Columbus would have been about 60-40 Democratic rather than 67-33 Dem.
If you keep the Columbus CD all in the City of Columbus, respecting jurisdictional lines, it becomes a Dem vote sink. In that sense, it is a "natural" Dem vote sink. I think that is reasonable.