Sure.
The problem with McCarthyism is that you're accusing people of being spies without any real evidence. They are, in all likelihood, innocent people being punished for no reason. It becomes a witch hunt and a pretext for punishing anyone you don't like but have no legitimate reason to punish.
By contrast, "spies exist" is a thing that we know is true. There have been documented instances. We don't need to know that there is there is a spy in a particular company at a particular time to know that we should take rational countermeasures against them. Encrypt everything. Eliminate centralization to avoid a single point of compromise for millions of people.
This can't be used for a witch hunt because it's defensive rather than offensive and isn't singling out any particular entity for special scrutiny. If we don't know which particular company or technology is targeted at which time, if we don't know if the adversary is Russia or China or organized crime or corrupt law enforcement, the course of action is still the same. Make mass surveillance as difficult as possible for everybody everywhere.