I haven't, but admittedly I've skipped several posts. I have seen quote a few people saying it's harder and being accused of saying it's hard. I have seen those people like my posts clarifying that while it's not hard to DM, it is harder than playing.
Heck, for many people playing is hard. It can be very difficult to carve out consistent multiple-hour blocks of time to engage in entertainment.
Being a DM is hard for some; much like knitting and birdwatching are hard for me.