Mounts along the top tube want to run the style of brake included with the bike the most proficiently.
When your brake is a side pull caliper, or cantilever, or V brake, the line wants to run as linear as possible, to provide the most direct path of motion.
The most you can do in most cases is drill out the mounts and slip the cable through them entirely; if you really have a problem with the exposed cable. The reason for this mount style is because it makes pretension for the brakes easier dealing with the small amount of cable housing that connects from the brake to the closest rear mount—and then the lever with the closest front mount. This pretension is what enables the brake to engage proficiently.
When dealing with the whole cable, it can complicate the process of cutting the housing to the proper length for proficient brake engagement.
Hope this helps.
The way the existing mount points are, you can have two drink bottles.
With your preferred location, you can only have one drink bottle.
I have mounted bottle cages in places where there are no mount points, using hose clamps. It is probably only realistic with certain types of bottle cages, and you need to be creative.
You could put the top screw of your bottle cage in the bottom mount point. That will be close to where you want it. Then you need some way of securing the bottom. You may need a different bottle cage.
By the way, you cant have mount points higher on the seat tube, as it will prevent you from lowering the seat.
Okay, yeah. Maybe I misunderstood.
I could supplement here that the higher mounts would be inclined towards things like locks or airpumps and keeping them away from the thigh rotation (by mounting them higher on the downtube). Also storage packs (for actual trekking and bike packing).
I agree. There are clamp-on brackets. There should be three points of contact to make it higher or lower