You've been wrong.
Personally I'm with you on this, but I'm thinking that you and I are probably around the same age and can remember a time where the market wasnt slathered in splatbooks and extras and that if we wanted to add something into the game that wasn't there we had to make it ourselves.
I've noticed that a fair amount of newer players & GM's want to do as little work as possible and if the adventure isn't exactly what they want then there is something wrong with the adventure. Whereas I think that people like you and my self aren't beyond changing things in a written adventure to better suit our players without throwing things completely out of whack.
Is it lack of creativity or pure laziness? I'm not sure but sometimes I get taken aback at how much people are unwilling play around with whats in front of them. I mean not to long go I had someone actually tell me that if youre introducing house rules into a game that means the game wasn't well designed and is probably broken. Never mind the idea that different groups can play the same game in completely different ways from one another....
I think this is 2 different things. I imagine most DMs customize most pre-written adventures to suit their group, weaving in subplots to link characters closer to the main plot, tailoring items, omitting things which might bore the group, adding things as needed. This is not the issue.
Taking a 4E module and converting it is the issue, at least for me.
Im not lazy and I dont suffer a lack of creativity, and im not sure I would like to be lumped under suck a blanket statement regardless. To me the hurdle is
TIME.
I dont have the time to create my own adventures like I did when i was alot younger (im 40 now for the record). I work full time, have a significant other (with a teenage daughter to boot

), I still enjoy my sci-fi movies, video games etc.
Last thing I want to do is convert rules, especially from 4E to 3.5/PF. I just dont have that much time on my hands.
More on track though...
I thought Goodman did VERY well with his 3E/3.5 DCC stuff? Maybe his 4E numbers have dropped (my assumption wrong or not***) who knows.
*** late edit Im assuming this because his DCC forum seems dead and lets face it, if Goodmans 4E stuff was going strong would we even have this thread? Its also been a few months since weve seen a new 4E DCC.
Id say publish some for 3.5 or PF rules and see how it does, then compare. I think PF is the better way to go, IMHO. As much as I miss the DCC line, and I really want to support Goodman again, I just cant bring myself to buy the 4E DCC stuff. Just my preference.