The card has other hotel rewards. I imagine their data indicates that many cardholders use the card only to pay for Marriott hotel stays. This is a gambit to get them to put the card in their wallets more often, on the chance it will also be used for other transactions.
Bingo! I ONLY use this card for Marriott stays and have often contemplated dumping it because it is so rarely used. However, it's always been a good deal because it's no challenge for me to use the $300 hotel credit, rendering the fee to effectively $150. I've never had a challenge redeeming the cert for a value of at least $150, so it's a wash and more often a plus.
The $25/mo on food is now a bit annoying but with ApplePay and GrubHub/UberEats, etc., the card can still be used each month and still doesn't need to be physically carried around!