I'm a big fan of buses or perhaps more accurately I guess semi intelligent pipes with semi intelligent endpoints.
I have used RabbitMQ (and Kafka at times) for large portion of my career and anytime I tell people this the bring up the single point of failure.
The single point of failure arguments is getting really old and is fairly baseless particularly if your storage (e.g. RDBMS) or network (single zone or even multi zone load balancer) is also not a single point of failure.
So to avoid this red herring of a problem for many who really don't need to solve that problem they create massively complicated endpoints.
This endpoint code is proprietary and often has to be deployed at the same time and creates fairly tight coupling. The Netflix Hystrix creator (Ben Christensen) discussed this issue at length here: https://www.microservices.com/talks/dont-build-a-distributed... (its also ironic that he built Hystrix and various dependencies which are sort of the antithesis of this... I guess 20/20 hindsight).
There are pros and cons and its not always "lazy design decision".