I never said anything about 'easily.' It's a very difficult problem. I am not saying there is a perfect solution either. But they arent even trying.
There are a lot of inter-related issues here but specifically the article is talking about botting. Basically botting just means automating repetitive tasks in the client. It's a very natural and predictable desire for anyone playing a game that involves a lot of repetitive tasks to find some way to automate them on the client-end, and if the client is a PC then the more technical players are going to find a way to do that. There is no technical 'fix' for this and acknowledging that is important. It cannot be fixed it can only be worked around.
Now we could go off down the decades long history of workarounds, but I will try to skip to what's important. You see, the main damage that botting does to the game is to disadvantage the people that dont do it - they find that they progress so much slower than the ones who do that they get disheartened and quit. The authoritarian game admin will reflexively respond to this by prohibiting the use of bots - but this NEVER improves the situation. The technical folks whose advantage he is trying to disrupt, are also the least likely to be caught violating the new rule. It's the other gamers that the admin is actually trying hard to retain who are most likely to somehow stumble into the world of botting, slip up and get caught, and then banned.
A better solution, in general, is to allow it and make it easy for all players to do, so that they are on a more even playing field. Because most of the burnt out players arent going to be stressing on botting qua botting, they are stressed on the fact that other people are doing it and they cant!
Now on a game with any sort of role playing feel to it, there is still another problem - bots running around skilling up or making money or whatever and not responding to you really blow the whole immersion thing. But once we have focused more narrowly on the problem there, it is not intractable. What we did on my old Mud was legalize 'at keys' botting (where the client is running a script, but the player is still near enough to see the screen and respond if needed) and only outlaw afk botting.
That worked great on a system with ~300 players and ~4 immortals on at any given time, but WoW may well be running with far fewer admins. Again, to save money. And look, I got no problem with them wanting to save money and make a profit, but do you have any clue how much money they rake in on this thing? It wouldnt kill them to hire a little staff.