The biggest barrier to entry is time because unlike web or other higher level software stack, blogs and github resources are no where near the level you feel like you can figure out how to make something work other than Arduino and RPi platforms. Want to learn how to code Beaglebone's PRU with rproc and not the deprecated uio? Good luck. Want to learn how to configure TMC2130? Good luck. In order to drive the micro-controller space forward, the IC manufacturers really need to produce thorough tutorials that newbies can understand and get up to speed, and keep them up to date. Just take a look at Deep Learning, which became popular no sooner than micro-controller world did. I can easily list 5 top tutorials and MOOCs where a newbie like myself can follow and get some meaningful understanding or output from it. Deep Learning is arguably a much tougher and vast topic as well.