You are right that several missteps were made:
-releasing certain titles on BDA without 5.1 mixes where one already existed ("Layla", etc.)
-only releasing certain newer 5.1 titles only on DVD-V and not BDA too ("In the Land of Grey & Pink", Mike Oldfield titles, "Roxy Music", Steve Hackett titles, etc.)
-only releasing 5.1 BDAs in more expensive box sets (Steven Wilson "Farewell to Kings" mix, "Pet Sounds", "Idlewild South", Soundgarden titles, etc.)
-not reissuing certain popular DVDA/SACD titles on BDA ("Eat A Peach", "Boys & Girls", "Avalon", "Crowded House", "Brand New Day", "Gaucho", "Slowhand", Elton John titles, etc.)
If Universal would have done more to alleviate these missteps, then maybe things would be different, but as of right now, Blu-Ray audio discs are basically a box set item as the major labels see it.