It feels to me like Arduino is becoming a shill for whatever processor companies want to market to people. Not that there's anything wrong with the RA4M1 or anything, but Arduino seems like they are less focused on ecosystem than they used to be.
It's more that the Arduino ecosystem is now so well-supported and wide ranging that it makes sense to have the association with it. e.g., I have an STM32 Discovery board on the table next to me that has the standard Uno pinout available in case I want to use Arduino shields. For prototyping using the ecosystem is insanely fast. In many cases it also makes sense for low volume production.
