Their worship services were full of people babbling nonsense. Paul rebukes them for this, saying, 1Cor. You might have been there yourself. Many people I know were once invited to Pentecostal churches. So Paul writes, 1Cor.
Many churches approve of everyone in the congregation speaking simultaneously in tongues.
This command has been thoroughly disregarded by them. I can't speak regarding their motives. The third examination that tongues must hold up under is that it must be interpreted. An interpretation should be given by someone who recognizes the language, so that everyone can hear and understand what was said. For example, in Acts 2, the multitudes were the interpreters.