I'm sorry to hear you were surprised by the way licensing works for X-Pack. Just to make sure it's clear, Elasticsearch, Logstash, Beats, and Kibana are all open source and do not require any kind of licensing (other than the Apache 2 license, but that's a different sort of license than we're talking about here). X-Pack is a "pack", which is a plugin for Elasticsearch and Kibana (and soon other parts of the stack) that contains additional features, like security, monitoring, alerting, graph, and reporting. X-Pack features are available based on your license level - most monitoring features are available with a free basic license, for example. You can see the details about X-Pack license levels here: https://www.elastic.co/subscriptions
You should only get the license expired message if you are using X-Pack, so it must have been installed at some point, either manually, or some other mechanism. Can you help me understand how you installed the Elastic Stack?
You bring up a very good point about being more proactive with the notifications of upcoming license expiration. Today, we show this information at the top of the Monitoring Cluster Overview screen, which you can click to see more details, including a link to the subscriptions page above. But we are planning to do more, as you suggest - we're currently planning to add a "toast notification" to notify you when you are within 7 days of license expiration, and will also be adding license management capabilities to the Management section of Kibana, and though I don't yet have an estimated timeframe for those to be released, it's clear they're important. We don't want folks to be surprised by licensing!
Thanks for taking the time to provide your feedback, it's much appreciated. If you'd like to talk or exchange direct email, feel free to reach out to me directly at my username @elastic.co