No suggested reviewers capability in the peer-review journal What is the implication of the peer-reviewed journal to state "you cannot recommend the reviewers"? (one can inform the "oppose reviewers" only). 

What good does the journal get out of such a practice? Just curious.
I completely agree with ff524’s answer about avoiding fake peer review, but there’s more to it than that. 

Asking an editor not to use a certain reviewer is reasonable, because there may be a conflict of interest or rivalry that the editor is not aware of but that could compromise the peer-review process.  However, what’s the purpose of suggesting reviewers? That seems really biased, since presumably most authors aren’t going to suggest anyone they don’t think will like the paper.

As an editor, I’m not interested in getting reports from reviewers chosen by the authors to have a positive opinion.  Instead, I’d prefer to use my own choices, and given that I’m not going to make any effort to follow the authors’ suggestions, I’d rather not see them at all.