I've been reading a book Christianity's Dangerous Idea by Anglican theologian Alister McGrath.
He brings up an interesting phenomenon. In the 1950's people were devoted to their denominations. An Episcopalian family would move to a new town and look for a new Episcopal Church. They'd not even consider looking at Baptist, Presbyterian, or Methodist Churches.
Now-a-days families are likely to change denominations when they move. Non-denominational factors are more important to church membership now.
A family is more likely to look for a Church where they find preaching they like, or fellowship they like or a child's ministry they like. The denominational identity is losing importance as people place higher importance on other factors.
In some ways I can sympathize with this. I will go along to Churches of other denominations with friends and family on occasion. I appreciate reading the thoughts and theology of people of other denominations. I even pull from non-Lutherans for my own theological views (mostly historical Catholics, Anglicans and Presbyterians).
However I don't think I'd switch denominations willy nilly just because I've moved. If I ever left the Lutheran Church it would be because of dire disagreements with the national leadership. It wouldn't be because I wanted to find a place with preaching that suited me or fellowship that was more comfortable.