Here's a hint as to why to keep closed source...so no one knows what sneaky things the developers are doing.

https://www.reddit.com/r/burstcoin/comments/c4v1yi/important_boom_coin_scam/

Crypto is about trustless systems right? Closed source does not follow this. It is just greed. Do you want greedy developers for a coin that you spend time, money, and energy on?

BHD also says they will be having open source "soon". More like "never".