Well, a solution for this would be a suggestion guide with fixed criteria. Players who want to make a suggestion that can be pinned could use these criteria when making a suggestion. Furthermore, one of the criteria should be that the suggestion must be liked from the devs (or by a huge part of the community). If someone meets the criteria, but the suggestion itself doesn’t fit into the game or is not in line with the vision of team radiant, then it won’t get pinned, no matter what. I think these would be accaptable terms for pinning threads.
This could work. Quite similiar to what 8bitCrab suggested. Combined with the suggested criteria, it could keep some of the good suggestions up.
This may be true, but it’s only one of many reasons why people don’t reply in suggestion threads. I started a suggestion some days ago myself and added a TL;DR version at the end of the post so that people with less time can read the suggestion. But it didn’t change much when it comes to replies. Here it is:
I got 2 replies effectively. Maybe someone else suggested an adventurer already, but I think my version of the adventurer would fit good into the game and is well thought out. I also tried to format my text as good as possible and like I said, I added a TL;DR version.
Great post. And I agree. Even if you don’t have much to say about a suggestion, just giving a “nice suggestion” or “I like it” is already a good contribution. It keeps a thread up, it shows that you are interested in the suggestion and it will certainly increase the attention a thread gets, when enough people reply. And with more attention more mods/devs will read the thread and also more people who want to contribute even more (a more analytical post) will recognize the thread then.