AVATAR NOT BY JIMMU
the existence of hoarding usernames so other people can't have them is going to part of the culture that comes with this privilege.
The only sites i've been on where this is a problem are sites with hundreds of thousands or millions of accounts. I feel like it won't be an issue here , although admittedly with the focus on the zelda IP there are a smaller number of usernames which may be specifically desirable. I feel like its the type of problem which should be worried about after it happens rather than before though.
If you can't make contributing posts with one account, then what is the second account actually for?
I've been on communities where socking was widely accepted and expected and a lot of people engaged in it. I can't speak to the reasoning of others, but I can speculate and I can express why I've engaged in it in the past.
1) Roleplaying - People might enjoy interacting with the community using a persona. They might make a funky kong account and then post on the community as if they were funky kong. They might want to continue using their regular account while they do this, or they might want to keep the actor behind the character hidden.
2) Fresh Start - People might enjoy re-engaging with the community under a new identity, and being given the opportunity to interact with the community in a setting where people don't already have impressions of them formed. As an example, someone in the MD section might want to engage in debates using a fresh identity to prevent others' impressions of them as a person from influencing their opinions on their arguments. Someone who is questioning their gender might want to try interacting with the community using a differently gendered identity to see what it is like. Similar motivations can exist in other social settings.
3) Expression - People might simply enjoy expressing themselves and exploring social settings using multiple identities or accounts. In the same way that someone might enjoy using certain words, or using a certain name or avatar, someone might enjoy using multiple accounts.