Arranger keyboards have always been designed (And conceived) for the home player market, (A smaller version of an organ that takes up less room and is cheaper to make, (Although not nearly as versatile) and as most home players have little interest in DAWs or external equipment, manufactures don’t bother fitting these facilities to them.
I must correct you in the case of Ketron - all of their equipment is for professional and semi professional musicians/singers/song writers/composers, only a small percentage end up in the home. The Audya is designed for solo entertainers (or duo's) that want the sound of a live band.
In the UK, 80% of our keyboard users are performing or recording musicians. We have people using the Audya for composition and recordings for TV and radio, others on Ocean liners, others in bars and restaurants, others backing entertainers, as well as weddings, parties and functions. And then of course almost every Irish Band that has a keyboard player will feature a Ketron. Accordionists, of which almost all who have invested in a Ketron Module do so because they are performers.
By the way....the Audya has six assignable outputs. Whilst limited it does give some flexibility. But its more for getting your sound right on stage rather than for studio work.