For more experienced type players, I think MOLLE is the clear winner.
I've shown my friends my CIRAS comparing to my panel type tact vest. For the guys who are in the forces (or experienced), they much prefer my CIRAS over the tact vest, but for new guys whom I'm trying to introduce the sport to, think the tact vest is a better choice.
My guess would be, new starting players aren't to a point where they feel the need for full customization since they wouldn't know how to customize in the first place (or at least they don't think they can before they buy), but rather choose to adopt the "regular" routines first before realize it might not be right for them. (Don't know if I explained this clearly or not)
Also, I think for a lot of players starting out, they don't think ahead for the long term. (ie changing to new guns or buying new guns, it's more like I buy one gun, pistol, BDUs, vest, and that's the end of it)
If you opt to sell molle only, it would be really newbie friendly if there are pre-made packages customized for certain models. (ie MOLLE system for AK-series, Armalites, G36, etc) I think a lot of new players would feel more comfortable buying a "solution". If I was starting out as a new player today, I look at the picture of the MOLLE system from above, I would be thinking, "Uhhhh, what do I do with it?" Where as the panel type would be, "Hey cool, I can put rifle mags in there, pistols mags, even got a pouch for my pack of smokes. I think I'll get that."
Perfect example, when I was looking into getting a CIRAS since it was getting good feedback left right and center, I didn't know what pouches/panels I would need or want, so I went for the pre-configured package instead of buying the plate carrier and individual pouches. I shifted around the pouches after each game until I felt comfortable, dropped pouches that I don't seem to use. Only now do I realize I didn't need some of the pouches in the first place or short on some other pouches.
Hope this helps