Why don't the pk3s that come with Tremulous come with .map files?

[MrWombo]

For example, ATCS. Why is Tremulous free and open source, but I cannot play it without maps, and the maps that come by default I cannot edit like I can Tremulous itself?

* MrWombo is confuzled.

[your face]

Because mappers don't want random newbies ripping off their ideas etc. without giving proper credit where it is due.  I personally think .maps should be included in the pk3s, but it's really the mapper's decision.  A great learning experience for a beginning mapper is to observe other .maps.

[mooseberry]

^^ What he said.

Tremulous is open source, but the works created (maps) do not need to include the source (.map). It is to the mappers discretion whether or not they will include their .map in the .pk3, and not all choose to do so, such as with ATCS, Karith, and Nexus6. Tremor and Arachnid2, for example do however contain the .map inside the pk3 for you to open.

[MitSugna]

Choose One:
a) They forgot to pack them?
b) They didn't want over 9000 version of the same map
c) They didn't want you to see the map source
d) It is a secret