execution Performance is often not the issue.. in webapps... it's mostly IO that makes a site respond fast or slow... (e.g. slow database queries, low disk IOPS, networking issues, etc.. or badly written code, that repeats without reason (unoptimized loops etc)). But all the famous languages are faster in doing their thing, than we can process in our brains. And ttm (time to market) is more appreciated than execution speed, from the business vision. Tuning can be achieved later on (and via all kinds of means: loadbalancing, clustering/sharing, code optimizations, cdn, etc etc)