You don't see the Nationalists marching through unionist areas on St. Patrick’s day or any other day. It's not even the marching that the nationalists care about. It's the fact that they have it rubbed in their faces every year. The unionists think it's their God given right to march "the Queens highway" and refuse (in some cases) to re-route the parade through unionist areas. You see it's not the marching the unionists care about it's the sectarian slap in the face they care about.
These day's it's like fighting over who has the best imagenary friend "my God could beat your God". It's all a load of old bollox.