In assessing the rights and duties of co-tenants, what are rents and profits?

Imagine if Amy and Bob are tenants in common. Together, they own Blackacre. Neither Amy or Bob live on Blackacre. Amy lives closest. Amy decides to build a workshop on Blackacre and, there, she creates custom furniture. She gets so good at it, that she starts selling what she makes. She sells high-quality, super fancy, super expensive chairs, tables, and cabinets.

Amy is making thousands of dollars per month, all possible because she has a workshop on Blackacre. Bob finds out and gets a bit jealous. Bob calls Amy and says, "Hey, I think I deserve some of that money you're making since you're taking up space on Blackacre." Amy tells Bob, "Nah." Legally, Amy is correct. She has no obligation to give Bob a dime. Since Bob has chosen not to make money using Blackacre, the law says, "That's fine -- but you're not allowed to freeload off of co-tenants who are making money." After all, if Bob wanted to drive to Blackacre and build his own workshop (or even make use of the one Amy has built on their shared property), he's free to do so. But what if he isn't?

Imagine if Amy decided to build a large fence and a locked gate, preventing Bob from accessing Blackacre. This would be an ouster, which would entitle Bob to a share of Amy's profits. Why? Because Amy has unilaterally and unjustly decided to prevent Bob from productive use of Blackacre, so the law says, "If you're going to be that way, then the profit you make needs to be shared with those who you are depriving of access to their property."

Next, imagine if instead of building a fence, Amy decided to rent out her workshop to someone else. Profits from such rental would need to be shared with co-tenants. Likewise, if Amy decides to let a mining company come on to Blackacre and dig it up for minerals, such profits would need to be split with Bob since the exploitation has reduced the value of Blackacre (untouched land is worth more than land that has been dug up and mined out).