Here's a newb question. Why are there so many fixed gear frames which are obviously meant for the street and not the velodrome not produced with two bottle mount braze ons? And why, on the frames that have one set of braze ons, is it usually mounted on the seat tube and not the down tube?

I've been browsing for a possible future build. My requirements are a quality butted steel tubeset with classic straight TT geometry, two bottle mounts and preferably top tube cable guides since I like to mount frame pumps and the clamp on mounts will probably hit it. I've concluded that a frame that also has a pump peg will never materialize. Not talking about a $2000 custom frame but one that is reasonably priced like a Wabi, Surly, ect.