When's a message queue too much for just handing out simple events?

We often use message queues like Kafka or RabbitMQ when we have really complex async stuff going on or when we need to scale up our microservices. But it seems like some teams are just adding them in for simple event distribution, like a 'user created' event that only has a couple of subscribers. So, is there a point where the extra work and complexity of a big message queue just isn't worth it? What do you think about using simpler publish/subscribe patterns or even just direct HTTP calls for small internal events?