ANSWER: It is wrong for the simple reason that it teaches those who (in error) perceive the “meeting house” to be the “church” that it is okay to use mechanical instruments in worship to God. Since both worship and weddings occur in the place of worship, they often hold that if the instrument can be used in the wedding, (often in accompaniment of hymns, which is as well sinful - Ephesians 5:19; Colossians 3:16) it can, likewise, be used in the worship service. Indeed, they (because of their misperception) see the inconsistency in what the church sometimes practices. Not only sinful practices, but anything that could detrimentally affect the destiny of a soul needs to be avoided, whatever the cost (Matthew 18:6).