Diversity, equality and inclusion ;-)However, regarding actual music... I personally think writing for the accordion should take into account the different types of accordion, and work within appropriate parameters so that music is playable on any system. I think it is quite common practice now to see adaptations within scores to open the music to all systems. Recognition and respect for different types of accordion is a good thing in my opinion.
The accordion composer Gorka Hermosa (who is a chromatic button accordionist) recently wrote a piece Meditatio, that received its world premier by Grayson Masefield - who not only plays a piano accordion, but with quint free bass. This is the sort of respectful and inclusive nature of writing that I find refreshing. I think it is good to appreciate the differences in accordions within a single family of instruments...
Seriously though, since getting a little obsessed with the music of Vladislav Zolotaryov, I've found a lot of the composing of music must have been done on a CBA as the progressions are so natural and fall under the fingers. I've also tried playing them on a piano and they are much harder!
BTW, this guy is great. I haven't really played 'real' classical accordion music before, just transcriptions, mistakenly dismissing the repertoire as either second rate or so untuneful/incoherent/pretentious that no one in their right mind would want to listen to it. This guy died young, but he is absolutely first rate.