Question about default settings

[pvm]

As described the documentation page:

Fixtures are used to load a "**fake**" set of data into a database that can then be used for testing or to **help give you some interesting data while you're developing your application**.

I do understand that fixtures can be used to warmup projects sometimes, but I think as the description says it's mainly used for testing/developing.

My question is: why we have the DataFixtures folder default to the src folder of the project, if it's main usage is during dev/testing? Why not default it to tests folder or even to a ./DataFixtures folder?
I understand also that I can customize the folder, but in the context of a application, if something is only relatable to tests, I think it should not be into the source folder. It's not required for the project to be working in a production environment (unless I need to have a warmup set of data or something like that).

Could someone please comment on this?
Thank you very much!