It'd be so monumentally stupid to ignore the problem if just spending more money on server/bandwidth would solve it that I do give SE the benefit of the doubt. It can't be the case you just need 3 times the bandwidth to check every 0.1s versus 0.3s, and at any rate the bandwidth used by a MMORPG is relatively little. I remember WoW had to change how often they checked the polarity buffs in Naxxmas during vanilia because it was lagging everyone up, and sure games were played on dialup back then, but even on a 40 man raid you'd think all the extra info you need to send to check a polarity buff would be the coordinates of other 39 players (3 integers) and their polarity status (likely a boolean).

So this problem is probably actually very hard given this game started with the wrong architecture, but just because the problem is hard doesn't mean it's not SE's fault.