A FlyerTalk Posting Legend
Join Date: Jul 2002
Location: MCI
Programs: AA Gold 1MM, AS MVP, UA Silver, WN A-List, Marriott LT Titanium, HH Diamond
Posts: 52,563
The MR Plat-to-UA Silver can be valuable to someone who doesn't otherwise have any Star Alliance status. Treatment on UA as a non-elite is utterly horrible, so even lowly Silver makes it a bit more bearable for someone who has to take a few UA flights per year.
But...general credit-card spend to get to MR Plat is a horribly inefficient way to get there. You'd need to spend $75,000 on the Ritz Visa, earning the points at a much weaker rate than you would using SPG Amex or some other card.
Of course, if you actually so some Marriott stays as well, you might be better off with the Marriott Visa which kicks in some EQN each year and effectively shortens the journey to Plat down to 55-ish actual nights, give or take...