I haven’t read the post in question. But to play devil’s advocate, holding 3 SPG cards takes up 3 of the 5 credit card slots that Amex limits you to. There are so many other co-branded cards to hit, particularly the Hilton and Delta family of cards, as well as Amex’s BBP and Everyday cards.
To add to this, DPs seem to suggest the FN certs from the Amex SPG cards post 6-8 weeks after the AF posts, which makes it difficult, if not impossible, to wait for the FN to post then cancel in time for a full refund of the AF, and Amex doesn’t prorate refunds after the 30 days. (I think I saw that the Chase Marriott cards’ FN certs post right on or very shortly after the anniversary.) So it seems to get the FN cert on the SPG Biz and Personal cards, you have to pay the second year $95 AF, and $450 AF on the SPG Lux. The question is then whether a 35k FN cert is worth $95 and a 50k FN cert is worth $450 (or an effective $150 after the $300 Marriott credit)? I think for some people, definitely. As an example, the 35k FN cert could’ve gotten me a room at the SpringHill Suites near
Disneyland, which was going for $299 when we were down there two weekends ago. For others, keeping the SPG cards for the FNs might represent a greater opportunity cost from not accumulating welcome bonuses from other Amex credit cards.
I suppose one could eat the AF to wait for the FN certs to post if the value of the FN > AF, then cancel sometime after the FN cert has posted to open room for more cards. But do we know if Amex has been or will clawback the FN cert if you cancel the card? I thought I saw some discussion about that a week or two ago.