Both the pictures are flawed.

The reward pool is not provided or produced by the witnesses. I explained this before.
They are workers that are compensated for validating blocks. The reward pool is produced by a mathematical function of shares x inflation / vests.

There is no ethical dilemma. For it to be a matter of ethics, it must be a matter of consent or property rights being violated.

The witnesses don't own the blocks. They validate blocks that the system compiles and sends to witnesses to validate.

Even if it worked like you claimed, it would still be completely ethical as no property rights or consent is violated. You are in a fair Vs unfair dilemma. You think it's not fair that content doesn't guarantee fish. If you want fish, you must invest, and even then it's not guaranteed that you'll catch fish or as many as you want.