There is a simple answer to that: When those who write those tactics did the boss, the nerf to mines hadn't happened yet and doing them was unfeasible in 10 man. The current (nerfed) version of the mines has so little HP they're a joke, but originally that was pretty difficult.
Another thing is, if you do the tactics without mines, there is only one difficult phase in the whole fight that lasts for about 45 seconds. Once you get through that, it's basically a kill. So just blow all CDs during the first Overcharged Magnet (and have people move out of missiles, blades and fire), survive that and you get a kill.
Here's a video from when we first did the boss (before the nerfs back in December): https://www.youtube.com/watch?v=KEYwOwPSSSo
The difficult phase is from 2:10 to 2:50. Note how we keep the stacking area free of fire and blades before that.