I was just reading the "Should I Buy This Frame?" thread, which is just the latest of many threads I've seen here where there was a large contingent of people expressing the sentiment that really nice frames should be built up with gears. This puzzles me.
Allow me to opine....
It seems to me that there are several possible reasons that a person would want a fixed gear bike:
1. You want a bike for track racing
2. You want a cheap bike
3. You want a simple bike
4. You want a low maintenance bike
5. You want to do tricks
6. You think fixed gear bikes are fun to ride
7. You think it will make a good project to learn basic mechanical skills
8. You want to improve your pedaling form
9. You want to work on your spinning and/or mashing abilities
10. You've heard that a lot of people like them and want to try it to see what the appeal is
I'm sure there are other reasons, but those were the ones I could think of off the top of my head.
Now assuming you more or less accept this list, it seems to me that if a person wants a fixed gear bike because of some combination of 3, 4, 6, 8 and 9 (and arguably even 7), there is no reason that any frame with horizontal dropouts should be deemed as "too nice" to build up as a fixed gear bike.
In my mind, the only difference between a bike "designed to be a fixed gear bike" and a bike that was designed to be a road bike but has horizontal dropouts is geometry, and in many of the cases I listed above road geometry is desirable.
So what's the deal?