Whilst I do not think ADF is that common as an approach these days I am surprised about how hard people seem to find it, learn the right techniques and it is no harder than a VOR!
I can do them, I just don't like them. I've never used one in anger, nor am I liable to TBH. I can do ILS and PAR in my sleep. Why in all honesty would anyone choose to do an NDB/DME approach at an airfield that also has ILS? Don't forget I'm not a commercial pilot or instructor so I'm not shooting approaches a dozen times a week. If you do them all the time then yes, I suppose they do become easier, but in a fixed card spammy I wouldn't choose to do one over an ILS.