Elasticsearch can handle it fine - but how do I use all that information in elasticsearch? I need some visualization tool. That tool is Kibana, which is not currently as powerful as Grafana (IMO). So the "problem" with elasticsearch has nothing to do with elasticsearch - it's that once I put my data into elasticsearch, I don't have off-the-shelf tools to visualize it as well as I can with InfluxDB (because data there can be visualized with Grafana)
The beauty of elasticsearch is that it can really handle both problems very well. I can easily put it "metrics" type information or "logging" type information - or just logging information and extract metrics. EG, using Grafana, I can only say "show me the graph of logins where the browser was chrome" if I stored that metric from the beginning (eg, metrics.login.chrome) then of course, if I want to see the chart of the different actions that chrome browsers make, I would have had to have stored that differently (metrics.chrome.*actions) With elasticsearch, I can just store my events and build visualization and ask questions afterwards. I think that is a huge difference and why we are building our system on elasticsearch.
For simple metrics that have no real properties (eg many os level properties - system load, file system usage) you don't need this extra power so it's much more valuable to put the measurements in a tool that gives you more power in visualization (eg grafana). But even here, I think there is much room for making richer logging and storing in ES. EG, for each measurement time frame, put all the different metrics in one record (eg {time:1436251626,load:3,disk_usage:"23GB",swap:"12MB",pages_in:20,processes:[...]}
. You can still build your metrics that same as usual (with the exception you need to use kibana instead of grafana) but you also have much more power. "Show me the top 5 processes when the load is over 2". Instead of seeing that there is a load problem and then trying to dig into which process is causing the problem, you can ask the question directly.
It's important to point out, that there is nothing inherent in kibana that makes it so it can't be more powerful. As Clinton pointed out, Grafana is a fork of kibana 3. I assume that kibana 4 was a major technological shift and the features are still catching up. I hope that process will be fast and we'll have a visualization tool that's as flexible, powerful and amazing as the storage engine powering it.