Master_Chen: In lieu of this, I'm making an open suggestion to the GOG's team:
1. Make installation of ScummVM an optional thing during the installation process of any of your good old games. Like, COME ON.
That would be silly because the game wouldn't work at all without ScummVM, and GOG support would be swamped with support calls "why doesn't your game work?!? I want my money back! In fact, I want everyone's money back!". Same with DOSBox games, GOG doesn't give an option not to install DOSBox with the game because then the game wouldn't run at all.
The games NEED ScummVM in order to work, hence it is included with the install. That is just common sense. And, the game does not install ScummVM system wide, so no it will not affect your already-installed ScummVM.
Master_Chen: 2. Make GOG's installing system ScummVM-aware so that when any user buys a new good old game and is installing it, the GOG's installer automatically determines (by scan, or etc) if there's already a ScummVM copy present in that user's system or not, and if it finds that one was already installed - first and foremost DON'T make GOG's installer install yet another copy AND at the same time bound/merge the newly installing game with the ScummVM that's already present on the user's system. Just one copy is enough.
Such a complicated system will easily break in the future when something changes in either ScummVM and/or Windows, and such a quasi-smart system would misdetect the presence of ScummVM. It wouldn't take more than e.g. ScummVM simply changing their version numbering, making it impossible for such a "smart" system to understand if the already-installed ScummVM is newer or older version.
The current, self-contained, way GOG games handle e.g. ScummVM and DOSBox is simpler, much more foolproof and future-proof, less likely to break. Plus, as GOG explained elsewhere, some things they've done may be also version dependent (of ScummVM or DOSBox).
Master_Chen: 3. Add all of the information necessary for the GOG's game descriptions so that any and all potential buyers would see immediately that ScummVM is being bundled and installed alongside the game itself when you're installing it for the first time.
Too much useless information will just confuse most customers. They don't even know what ScummVM or DOSBox is, and it isn't even necessary for them to know. They just want the game to work.
GOG could just as well list with each MS-DOS game which sound cards the game supports, but again that just confuses most people who have no idea what is a Roland MT-32, SCC-1, Gravis Ultrasound or Adlib Gold. To me such information might be useful, but not to 99% of customers.
StingingVelvet: The games GOG sells that use it work perfectly with the included version.
Master_Chen: Why not make it better when it
could be made better, though?
GOG is a business. Like any business, they try to avoid doing unnecessary work because that costs them money. They have to pay wages to the people who are supposed to update the ScummVM version on all those GOG games which use it, and thoroughly re-test those games that the new version does not cause any unforeseen problems.
There should be some real benefit in going through all that extra work, a benefit which would turn into more sales with those old games. I am pretty sure you will not re-buy all those ScummVM games if GOG updated the included version to 2.1.0.