Here's my take:
1. This is a discussion forum. 'God vs no God!', is a topic for discussion.
2. The debate over the nature of the universe is ongoing.. lasting longer than any other debate in the annals of human history.
3. Opinions and beliefs are always matters of debate.. mathematical formulas are not as provocative.
4. Interest in philosophical topics about the Big Questions never wanes.. that has remained constant for millennia.
5. Topics about deeper philosophical issues have interest to deeper, inquiring minds. Shallow people talk about people and things.
6. Some are perhaps insecure in their beliefs, and want/need to bash other's beliefs to compensate.
7. Some people will argue about anything.
8. Some people may actually be seeking Truth, and hope to find it in an internet forum.
9. Some people are proselytizing propagandists, with no interest in reasoning or discussion, just promoting their beliefs.
10. The Official State Religion of Progressivism may ban debates or open discussions about philosophical beliefs some day, mandating homogeneity of belief. Some may enjoy the last gasp of freedom of conscience and expression, before it ends.
..maybe there are more reasons why people enjoy debating these cosmic mysteries. This probably covers most.