They’re just not committed to a 1×11 solution for all (which is quite a UK based demand anyway), they’re going for a more holistic groupset – hence the doubles and triples.
Clever IMO – don’t try and compete head to head with SRAM, go for the (huge chunk of the) market that SRAM are basically ignoring.
The downside is that you don’t get some of the ‘SRAM specific’ benefits – wider cassette range, better chainring retention etc.
What’s SRAM got to do with it?
I assume it was just an observation that it’s not just Shimano doing proprietary BCDs…