The problem is that BIAB's midi resolution and 2 bar pattern limitation isn't up to capturing the performing dynamics and subtleties of phrasing you can achieve with Real Tracks.
For this reason and want of a more expensive midi module with larger samples, Real Tracks will always sound better by default to many people.
But this isn't some immutable truth; it's just the way PG have chosen to develop BIAB.
If midi patterns of 4 or 8 bar length were achievable as standard without the need to use bar masks then this would allow for more natural sounding comping patterns to emerge in midi without the clunkiness, lack of continuity and random quality you get with a two bar limit.
I guess it's the question of whether BIAB wants to become a true arrangers platform as opposed to mainly a performer's instant practice tool. Most people are happy with the ability to generate an instant sketch or 'arrangement' of sorts, even if the dynamics and variation of a real band are often missing. Shots and holds and pushes help but are not the whole answer.
Midi styles need to be more internally varied mirroring real practice in a performing situation. User defined chord voicings should be achievable and the oft-asked for ability to have chords entered on an eighth note time base .
These are the kinds of arranger-friendly possibilities BIAB has shied away from in the past five or six years since real tracks/real drums first became available. Questions of sound aside, audio loops are a done deal editing-wise and they can take away as much in creative flexibility just as they add in authenticity.
Regards
Alan