Dwarf seems like a strong word considering Columbus is #15 in population according to the 2010 Census; Cleveland is #45 & Minneapolis is #49. I also included other cities with a NBA franchise and Seattle.
1 New York City NY - 8,175,133
2 Los Angeles CA - 3,792,621
3 Chicago IL - 2,695,598
4 Houston TX - 2,099,451
5 Philadelphia PA - 1,526,006
6 Phoenix AZ - 1,445,632
7 San Antonio TX - 1,327,407
9 Dallas TX - 1,197,816
12 Indianapolis IN - 820,445
13 San Francisco CA - 805,235
15 Columbus OH - 787,033
17 Charlotte NC - 731,424
18 Detroit MI - 713,777
20 Memphis TN - 646,889
22 Boston MA - 617,594
23 Seattle WA - 608,660
24 Washington D.C. - 601,723
26 Denver CO - 600,158
28 Milwaukee WI - 594,833
29 Portland OR - 583,776
31 Oklahoma City OK - 579,999
35 Sacramento CA - 466,488
40 Atlanta GA - 420,003
44 Miami FL - 399,457
45 Cleveland OH - 396,815
49 Minneapolis MI - 382,578
53 New Orleans LA - 343,829
79 Orlando FL - 238,300
Columbus continues to grow in population each year; while others like Cleveland sadly continue to shrink.
Cleveland
2000 (478,403)
2010 (396,815)
Change (-17.1%)
Columbus
2000 (711,470)
2010 (787,033)
Change (+10.6%)
Ohio State and the location of major league sports teams in Ohio is probably the best argument for Columbus not having a team. Columbus certainly has the population requirement and continues to show strong signs of growth.
I still think it would be great for Cleveland to play a few home games a year down in Columbus. So many people have moved from northern Ohio to Columbus and would love to be able to see their team play inperson without making a big trip out of it. They could even be weekday games and I'm sure they would sellout.