It's not a poor man's drum recording technique, it's useful for rock, jazz, etc. Actually, if I am not mistaken Led Zeppelin have used mostly this technique (well, not really, but The Recorderman is a modification of the Glynn Johnes technique, and they are similar) to capture the drum performance, and I doubt they had problems with number of mic inputs available. Then again, I am sure they were using killer recording spaces.
For metal, sure, it'd hardly give any good results.
Fair point, but when you're only doing 16 to 24 tracks to tape with a full band...Then I could see the value of this technique.