I have been using 10' rods for Trout since 1985, when Scott custom made a "G" Series up for me in 5wt. I now have several 10's made by Sage, Winston and Loomis. They have been used all over the West by me and my kids for nymphing, dries and streamers. I have my eye on this one for a next:
http://www.thomasandthomas.com/rods/ats
There is no good reason to NOT have one...
...especially when one wants to work the soft water on the other side of the white water when the flows are blowin' on the East Walker River...
PT/TB