I really don't understand why this isn't allowed. I only saw "safety reasons" implied, and even so, if you join a server that endangers you or your computer, that's kind of on you.
Why do I say this? Well, I currently run a server with a modpack enabled. It is extremely frustrating that setting a command as simple as /gamerule keepInventory true is impossible. I've looked on Reddit, on Aternos Support, on any other forums I could get my hands on, and people have had this same issue. The rule never stays. Anytime someone goes into the Nether or the server restarts, the rule is reset to false. Why?? The only solution to this is to go in the config folders and manually edit the file, then set it to "Read-Only". But guess what? You don't have access to the config files. So ???
I feel people should have access to these files as it would allow more control over servers. Yes it's dangerous, but to be honest, if you're joining someone that has the ability to make a harmful server, you should reconsider who you're in contact with. Also, there should be consequences for said people abusing the power of the config folder.
If there's a solution to this that doesn't involve the config files, that would be greatly appreciated. But from what I've seen, there's no such thing. It's frustrating. Maybe I'm asking too much of a free server hosting service, I don't know. But I know there's many other people with good intentions that would like to be able to have the config files handy.
Thank you for your time.