Having a conversation on Twitter is like gabbing in the front row of a rock concert. You have to yell to be heard, and that annoys everyone around you. Yet for some reason, people engage in hashtag chats on Twitter. Hashtag chats are not only rude, they're unnecessary. There are far better alternatives.
Hashtag chats are often thrown by marketers who think it's a super-fun way for “people” to “engage” with their “favorite” “brands.” They're also used for regular get-togethers like #wjchat or #educhat, ususally around professional topics. Conferences use them to bring together participants, and publications use them to drum up discussion around articles.