That doesn't have to be the case now, particularly for plays written for schools, churches and community theatres. Most play publishers will send guidelines about what they expect in terms of submissions. Meriwether Publishing Ltd. PO BOX 7710, Colorado Springs, CO 80933. Publishes plays for secondary and school markets, and plays for mainstream churches. Other Churches occasionally do plays.
Some coffee houses allow artists to stage works.
A glance at the list above should alert playwrights that some plays by their nature should be submitted to particular theatres. Sending a play with a cast of twelve and elaborate sets to an arts theatre is misguided. It risks being considered unproducible just from a glance at the cast of characters and set requirements. The same play, however, could find a welcome home in community theatres or as audio theatre. You've written a play.