Sarcasm. Remember how quickly they cut that core exploit down? Now remember for how long we've been asking to fix this AFK issue that only became even more so apparent with Solstice-schmolstice, along with many others. Had it been addressed? Nope. Hence "no need to fix it". Basically, seeing something "fixed" as fast as they did with cores exploit, gives you true time-frame needed to implement something and push through platform holders chain of control. Anything longer means they just chewing glue. Or, if you very pro-bungee - they "playtest it". Probably in that invisible crack team or whatever.

Reason I'm so sarcastic towards bungee is because as far as I know, many developers gather telemetry of all sorts. Microsoft likes to brag on number of shots made, enemies killed, and so on. Remember Valve's Team Fortress 2 heatmaps? Same from other games? I have some friends who works in gamedev and I asked them about telemetry, truth be told, I was very surprised to learn amounts of data they assemble even in games I never thought it was... needed. As it helps to smooth out gameplay, and make it less... abrasive. All this includes various "hints" on where to go (without going overboard and painting all ledges yellow), what to do, etc. Thus, spotting, tracking, and implementing proper protection from AFK/idler mechanic is not that difficult. I mean, if indie (real indie, naturally garage team) can do that, I see no reasons why such big, grown fat from strength company can't. If it's not implemented - this means they give a fvck.