You can blame citation-counting and h-indexes for a decent amount of that latter part. If administrators who don't know enough about an area to individually judge the quality of someone's record are mainly using citations and h-index as proxies for quality, then the job of a junior researcher becomes to maximize those two numbers. There are various strategies for doing so, but one of the higher-probability ones is to churn out a lot of papers, and also to make them relatively similar to what other people in the field are already doing (so they'll cite them as related work in their next paper).
