Firearms change technology. They change how buildings are structured, they change how wars are waged, and they change in some aspect how cultures think and approach politics.
I love the tamriel where the traditional weapon of the blades is a Dai Katana. Where swords, magic, axes, spears, bows, crossbows, and such weapons are all the populace has to defend themselves. Well, thats must how I feel. Not saying I hate guns or that its an entirely bad idea. Just saying I love the elderscrolls where they're at right now. The eras may change, but it will always be a medieval flavored setting.
That was very nicely said with another like that you will beat my stubbornness maybe.