So, if I understand correctly, unless you are actively shoveling money at WotC, you are not a fan of D&D?
From an investor viewpoint, you don't have to be shovelling money, but a fan that does not result in some money coming in somehow (and there is always an angle to get a fan to spend money, whether it's just a sticker, a t-shirt, begging a friend to make an account and then seeing ads that pay money...etc) coming it...it's not really a fan worth counting. I mean, even kids will go somewhere and see ads (that bring in money). There has to be some excitement somewhere, some way they participate in excitement...even if that translates into a player who gets their DM to spend money (hence why I think the 1:5 ratio works in the first place, that's not saying everyone in the group is buying a PHB...but someone in the group will in order for them all to use it...some may just use the free basic rules...or something else...etc).
So...not shoveling money, but excitement and involvement leads to money being spent...not necessarily a whale (and face it, only 1% or 2% are whales), but at least a minnow. (I think statistically they say around 10-20% will at least spend money on a product, which falls in line with 1/10 to 1/5, but with outiside involvement from others, other sources can push how much is spent upwards, even if still from only that lower percentage).
PS: Personally, I'd prefer you to spend money on quality items being produced, as both the company that made it and the person buying it both benefit from that transaction.