Flight of the Amazon Queen and Drascula: The Vampire Strikes Back is avaliable for free on scummvm.org website, why not offer these titles for free on GoG.com? =)

Because it takes the staff time and money to make sure these games will work properly. Just because it is supported by SCUMMVM doesn't mean they can just wrap them up and throw them out there.

I just want MM6 now. The wait is robbing my sanity.
/salute the GOG machine

I understand.... but I suppose that everyone can spend 10 minuter per week for 6 months to release that on the future XD

Even if the games are available for free on the ScummVM site, doesn't mean that just anyone can offer them for free. For all we know, there is some kind of licensing associated with those games that means it is only legal to get them directly from the ScummVM site. Besides, while free games are nice, no one comes to GOG for the freebies, they come here for the retail selection. Better that GOG focus all their limited time on getting more of the non-free games we want rather than some freebies that aren't necessarily wanted and certainly aren't needed to grow GOG.