Ofcourse they should be allowed to, that is like asking should BTC be allowed to exist, no? I say more power to them but best to improve upon the foundation Bitcoin has laid out. I think it could be a good way to generate money to their economy and can't blame them for trying it out.
This looks like a step in the in the right direction...
Question: Wouldn't there be a legal issue if they use Bitcoin tech (particularly blockchain tech) and not keep it open source? How would the open source license be enforced?
No.
Bitcoin is licensed under the MIT License, which does not require sharing of derived source code:
https://github.com/bitcoin/bitcoin/blob/master/COPYINGCopyright (c) 2009-2014 Bitcoin Developers
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
If the only library is closed source, then there's a project to make an open source one.
If the only library is GPL, then there's a project to make a non-GPL one.
If the best library is MIT, Boost, new-BSD or public domain, then we can stop re-writing it.
I don't question that GPL is a good license for operating systems, especially since non-GPL code is allowed to interface with the OS. For smaller projects, I think the fear of a closed-source takeover is overdone.
