this is pretty much my take as well - but as a non-employee - I was a big fan and user of twilio when they first came out, even attended the very first few twiliocon conferences in SF, (mostly developer focused) where they would announce and release new features - lots of excitement as new things got announced and rolled out during the annual conferences.

Then after not very long, you would goto the conferences where they would make announcements about what is coming, but no real timelines attached and some things that were announced, never really materialized - or not fast enough etc.

Then they started diversify like crazy into other areas, unrelated, and I think they really lost their focus - stopped using them (99% stopped) a long time ago for those reasons.