Well , I believe it all depends on how you see your account from on set. For me, while I was creating my account, I decided that this would be for all niches. However, things changes but I haven’t made that decision yet to change the type of content I post with this account. 

I’d go for  1 account for all niches except you’ve got a project that will be running on Hive then you can create another acount for it.