It's a lot to do with marketing and presentation.
It took me a while to work out what the Blackguards KS was for.. and most people would have walked away long before..
It does look good, although I am not sure why I want Blackguards when there is also Tombpunk..
I have to say they look very lovely rpgs and I would enjoy playing them, but I am already too confused to back it or simply buy Tombpunk on drivethru.. and that confuses me.. why am I backing an RPG which is based on a rpg that is already on drivethru?
I think this is spot on. It was for similar reasons that I released Modus Operandi as PWYW. In the 6 weeks (tomorrow) since I released it it's had over 200 purchases (17 of those were people spending their hard earned cash on the PDF or a POD copy). Even with the best will in the world, I doubt I would have gotten as many sales if there was a set price.
I've backed ACE! https://www.awfullycheerfulengine.com/
It looks a lot like a lite game I made once, but with a load of scenario support - and that's all I want these days: lite rules, scenario support. My brain is too full to read 200 pages of setting and 150 pages of rules, and write my own adventures.