You seem to be thinking that, if an action is good, or OK if done by /any/ party, then it must also be allowed/OK for a monopolist. However, that's not the way it works.
Monopolists are barred from certain actions NOT because of anything specific to the actions, but because they ARE a monopolist. Monopolists have to have their grip prised from the market, and this requires barring them from taking actions that would be perfectly acceptable, even desirable, from other actors. This is needed to create room for other actors to expand in the market.
Your comment shows a fundamental misunderstanding of the theory behind anti-monopoly law and regulation.