ABC lines were added to prevent basecamping so the admin wouldn't have to do anything in this regard. It's not a 'safe zone'. Going right up to the line and shooting inside it should be perfectly fine, that's how it's designed.
But do you design the maps to frustrate players or do you want to get them on the flags (targets) and into fight - at the end
playing the game? On alot of maps I can manage to cause total havoc with my squad in the enemy base, if it wasn't forbidden by server rules.
You have to imagnie the worst case possible. In this manor the German base at St. Vith is a deathtrap at it's best. Why do I start FH2, if I get slaughtered anyway the moment I spawn? - because then all gameplay mechanics fail and people ask to skip the map, what makes the map itself and alot of work totaly useless at the end. Thanks to all server admins that this isn't possible.
@Pureperversions: We had this discussion with Fair Player in the 762 forum and found a consense. You don't have to shot in there. Use your brain a littlebit to kill him and find a better position. You can still kill him the moment he exits the ABC line. I always ask myself how we manage to play the game on 762
People don't have the fun to play the game in mind (for all layers), but only a fast and easy kill.