By using the license one can still use proprietary software to interface with the API as the data generated by it is not under the license (only this code is). Mainly this license disallows anyone to use this specific API code without stating changes and disclosing source (assuming it has been modified). The license does not disallow commercial use.
Compared to the old license, it's much clearer for what and how the code can be used (it has also been used much more) and how hosting modified version of this back-end obligates the host to disclose the source.
By using the license one can still use proprietary software to interface with the API as the data generated by it is not under the license (only this code is). Mainly this license disallows anyone to use this specific API code without stating changes and disclosing source (assuming it has been modified). The license does not disallow commercial use.
Compared to the old license, it's much clearer for what and how the code can be used (it has also been used much more) and how hosting modified version of this back-end obligates the host to disclose the source.