The motivation behind the MicroProfile initiative was to build upon the Java EE standards and create smaller-scale profiles that target microservice architectures as well as experiment with features independent from standardization. Multiple application server vendors have been involved in this initiative that forms vendor-agreed de facto standards.
Server applications that support MicroProfile pride the opportunity to run Java EE applications that only require a smaller set of standards, in the first version this includes JAX-RS, CDI, and JSON-P. Similarly, application server vendors provide the ability to strip down runtime to a specific required set of standards.
The advantage of these approaches is that they don't add dependencies to the enterprise project, rather than just optimizes the runtime. Developers still write their applications using the same Java EE standard technology.