Well, the commitment would be $75k, but the money can be spread across up to 8 travelers on same PNR, isn't it? If I understand it correctly, someone depositing $75k to an individual PassPlus account gets the GS benefit at the outset and can then proceed to spend $37.5k on themselves and $37.5K on a companion out of the account. Unlike the rest of the GSs, the PassPlus GS status benefit is not dependent on individual spend, but on the $ initially deposited. Up to 8 companions are allowed on same PNR, so the theoretical individual PQP spend could be $8334 and be GS. Individual travelers are the ones most impacted by the jacked $ commitment, as well as those who travel with others who just don't get to that level of spend.
If one initially gets GS via PassPlus deposit, that person would need to make another deposit for the next contract period to continue the GS benefit or hope he/she has enough individual spend to qualify the normal way.
I think the raised commitment is a reflection of the raised flexibility (i.e. the new up-to-8 companions). The $50k (IMHO) has been a simple workaround, for some, relative to the normal qualification process. Plus, UA thinks they can