There's no doubt Gemma's license is less permissive than other models and that it has less community finetuners for that reason.
Here's OSI's argument about this when Meta's llama put such limitations in their license: https://opensource.org/blog/metas-llama-2-license-is-not-ope...
https://www.gnu.org/licenses/old-licenses/gpl-2.0.en.html
There's no doubt Gemma's license is less permissive than other models and that it has less community finetuners for that reason.