I reached Rank 11 (of 14) in the old, pre-TBC honor system. This was a time when the only battlegrounds were Alterac Valley, Warsong Gulch, and Arathi Basin (still the best by far in terms of gameplay and balance). I understand your woes, Friday, having done literally hundreds of WSGs in my day. Just as an aside, flag carriers have had the damage debuff and have appeared on the map after a short time since vanilla. I'll give you the reason why you can't capture while your flag is away, with my literal man months of experience on the map. Druids and, to a slightly lesser extent, Shamans. If you could capture while the flag was away it would just become a race between all the druids, with other players trying to run interference for them. One crafty druid could win the game in a matter of a few minutes of unchecked, which I've seen happen many times.
I am not saying this is a good thing. I haven't PVP'd "seriously" since that time, and I consider competitive PVP in the context of WoW to be an oxymoron, but that's still why.