I think the 'money for honeymoon' request, is just a polite way of saying we would rather have money than a object - surely most honeymoons are budgeted and part paid for, if not totally, by the time of the wedding ? The couple aren't going to be totting up the cash and saying ' whoop, undo the suitcases and repack, we aren't going for a weekend in Brighton, its the Maldives for us ! '
Giving cash has been the custom in many cultures but not so much the traditional British one - we have become a more mixed society and aspects of our etiquette are changing . Giving cash at a wedding used to be from family members ( parents, grandparents , rich Aunt Lucy if you were really lucky) with other guests giving physical presents, with a list to guide them if they wanted it but with no obligation.
I remember going to weddings as a child, with a gift table which displayed things like kettles, crockery and tea towels on it because the couple were setting up home for the first time; when we got married, we already had the basics but had a list, if people asked , of an expensive dinner service ( as was the fashion then) that we were very happy indeed to get just a piece or two - accumulated gifts made up the entire set ! We also had lots of random gifts, all of which were appreciated. One SIL gave a trug, , with a set of gardening equipment, itwas our first tiny garden - that was so thoughtful and not something that would have occurred to us. People brought gifts with them, but they weren't displayed. My DD is getting married this year, was very reluctant to even consider gifts but has complied an online one because that is how most people we know like to do it now - all buying done in a few clicks and never seen by the giver, including some charity donation options.
I don't think there is anything wrong at all with saying money is an acceptable option - couching it as honeymoon contribution is a politer way of doing that. The couple are saved the bother of compliling a list of items. A thoughtful, personal, gift still a lovely idea, though - the hamper sounds delightful.
Gifts used to be part of the marking of a new, joint life - the equation I have seen on this thread of ' food and drink provided = cash sum expected ' misses the point of a wedding.