For the 90% use case, having a default setting for amqp_consumer_id is better than the current default. Setting the amqp_consumer_id by default would make chef-solr-indexer always use the same queue name (and make the queue persistent). The primary benefit of this is that users won't have "abandoned" queues that can possibly fill up with data and eat a ton of RAM.
The only advantage of using a different queue names is in the case where users are running multiple chef-solr instances for redundancy. This is a more advanced use-case and not the default, we should tailor the default config for the default installation.