[mjn]

Limiting choice is BAD. The whole reason you should be creating and using free software and OSS is to not weld the hood shut.

But you sound like you want to limit choice for users. The whole point of free software from the GNU perspective is to keep options open for users, and not allow downstream devs to "weld the hood shut" on derivatives by adding more restrictions on what users can do with those derivatives.

However, there are other reasons people choose it as well. One motivation you sometimes encounter is a view that, if someone's code is used in proprietary, commercial software, they'd like to be paid for it. Hence the dual-licensed model used by libraries like Qt and the Stanford Parser: you can use the GPL version if you're willing to GPL your own app, or you can buy a proprietary license if you aren't. Seems reasonably fair: I give you my code free if you reciprocate and do likewise with your own code, or I sell you a license for cash otherwise.

[H3g3m0n]

If someone is wanting to go with the full GPL I think the AGPL would be a better fit anyway otherwise people can use a webservice to do all the processing. Could even charge for it and not give any in house changes back.