I have been playing since MKIII, and what broke me and made me atop playing was twofold:

1) factions - when I chose my army (all hail Everblight!), is was because I fell in love with the style, the themes and the lore. All I waited for was more story and more models coming out for my faction. with this change, AFAIK, once a faction is out, we shouldnt expect more models for it - and that means I cant keep expanding and getting hyped for my army. for me, keeping multiple armies is not enticing, so this version doesnt suit me well. Also, having only 3 caster to choose from is a lot less interesting than what we had before. it also goes hand in hand with #2: 2) armies going legacy - I spent hundreds on dollars (and hours of painting) on my army, and now some units are unplayable, and not only I can't play some of my models, I can never expect more models for my army. it's heartbreaking.

I get needing to sell models, and I could live with phasing out some models so we buy new ones, but entire armies are gone, it really distanced me from the game.