Bellingham is twice the size of Nanaimo so I don't think it's a fair comparison.
But MonkeyRonin is right in that Nanaimo is a small town stuck in the midst of a giant suburb. Its urban core is nice enough, charming even, but it's tiny. Courtenay is a fraction of the size and yet it has a similarly sized downtown. Hell, even Duncan has a downtown area that isn't much smaller than Nanaimo.
Aside from downtown and the adjacent "old town" area, there's working class bungalow belt that is kind of dumpy, and then endless sprawl that is shocking for a city of only 100,000 people. The location is great and the natural setting is gorgeous, but Nanaimo definitely punches below its weight.
There's a lot of potential though. It's a very linear urban area, so if you revamped the old E&N tracks into a kind of interurban tram-train running from Nanaimo Airport up to Qualicum Beach, you'd have a chance at creating a proper city.
__________________
¯\_(ツ)_/¯
|