Why some people are extremely averse to RabbitMQ? I saw that at one company having RabbitMQ / Celery setup - every time a new software engineer comes in, they

Why some people are extremely averse to RabbitMQ? I saw that at one company having RabbitMQ / Celery setup - every time a new software engineer comes in, they complain about RabbitMQ and ask why would company use it. The infrastructure was running like this without hiccups for years. At one point company has let go of many experienced engineers and this time one developer found some issue with the code and blamed it on rabbit as it was locking the queue. There were no more senior developers to contest it, so he convinced manager to swap it out for Redis. He took about two months to rewrite it. Surprise, the same issue existed on Redis. The Redis solution works fine, but has its own limitations...