So I make a pile of sticks, that pile of sticks is open source? No.

You are confusing using open source tools with being an open source project. Using open source tools is great as a user, but it does not make what you do with them open source, whether it makes the activity legal or not. Publishing the design of the tool to be replicable by others is what made that tool open source in the first place for you to use.

It is the difference between "I built this house out of bricks woth my open-source backhoe" and "I built this house out of bricks this way, and here is how you can do it the same way". Neither one is illegal, but one is an open source project and the other is just permissible under the law.

Public Domain =/= Open Source either.