The region never properly industrialised in the 19th and early 20th century. The basis for Quebec's industralisation was access to the Iron mines in the Labrador Trough. For Ontario it was access to the prairies. For the Maritimes they industrialised using wooden ships and sugar mills using British West Indian sugar cane.

But wooden ships were replaced by steel ones and sugar cane cultivation in the British West Indies declined owing to new competition in Brazil and the development of sugar grown from sugarbeets. So the two pillars of maritimer industry went bust. Now that we live in a post-industrial era they've basically missed the chance for capital to accumulate and for urban centres to develop in the same fashion as had happened in the rest of Canada.

I don't know what the solution is, but I do know that the government isn't really looking for one either, and whatever it may be it would be expensive and politically difficult.