One of the strange things about Sonnet 94 is that the speaker almost never out-and-out tells you what he thinks about the powerful people he is describing. That is to say, he almost never writes something like "I'm praising these powerful people because of x," or, "I'm criticizing them because of y." In fact, the only place where he really comes out and says what he thinks is when he sticks the word "rightly" into Line 5, to tell you that he approves of the fact that the powerful people "inherit heaven's graces." That said, we do seem to get a sense of admiration from the way the speaker portrays the powerful people. But why? Is it because they have power in the first place? Or is it because they choose not to hurt people with that power, even though they could?
The speaker admires people who keep their emotions under wraps; so why would his poem lay it all out on the table?
The speaker doesn't admire all powerful people—he only likes the ones who exercise that power with restraint.