IBM doesn't think that way. They're probably using "the longhair hippies can't use this hardware" as a selling point.
The article already lays out the field: The infrastructure groundwork is done (compilers, linux distros, ...), in no small part thanks to IBM funding such efforts. The main limit is hardware availability and overall mindshare, not infrastructure. If you have a reason to develop for POWER it's easy and reasonably well documented in my experience, the problem for the ecosystem is that few people have such reasons. (i.e. you're either an enterprise supplier like SAP or a bunch of nerds at an uni or with a raptor box at home, little inbetween)
You can use google nowadays.
1. https://www.ibm.com/products/xl-cpp-linux-compiler-power
2. https://community.ibm.com/community/user/power/blogs/si-yuan...
But at least when i was there, IBM's interprocedural middle-end (TPO) was some of the nicest and well structured C++ compiler code i had seen in a long time. It was well written, well commented, and well architected.