I don't really have a problem with these 'tactics' per se... more with my own teams incompetence to recognise what is happening and what to do when someone is going on a rampage behind our lines.
They just run through a corridor filled with dead teammates while ignoring the side and VOIP chat and also doing a great job at not noticing that the kill feed is going mental with a single name on one side. This obviously gets a lot worse during sales and free weekends.
Whenever I'm on the sweet side of the barrel I rarely see more than 2 people trying to actively hunt me down. IMO this whole thing is comparable with those newbies who keep running into the same artillery barrage several times, it's not an exploid of the Commander who placed it there - it's just lack of.. well, a lot of things. However this stuff is in a very grey area with no clear line, some maps are just so poorly designed that effectively fighting someone who keeps flanking your team is simply not possible and imo outright broken when I happen to be SL1.
For example on Pavlovs when I rush through the tunnels (glorious PPSHh-41 and some aiming) into the actual Pavlovs house and sneak to the sniper attic as a Squad leader there is almost no way to get rid of me and my respawning squad members who can happily shoot into the enemy spawn (actual spawnkilling) or prevent every Russian soldier from advancing into C and partially D. This is just one spot, there are countless more but I assume most of you know them, regardless if you use them or not.