To be fair, and as you admit yourself, it's hard to come up with a valid reason as to why an airline would even want to give status to someone who spends less than a few thousand a year on their tickets. And I say this as a 90% leisure traveller.

I ditched *A for ST exactly two years ago (and I'm very happy about the divorce in hindsight), but I clearly remember the sheer number of A3 *G at LH lounges and on LH flights in my last year of captivity. A3 have probably finally decided that the kickback isn't worth the overhead.