Every Barca fan here can tell you Valverde underused Dembele.
I mean, not that people on a hockey forum are a measuring stick for truth - but I do wonder who else aside from you says this.
Again, Dembele was bought last year, given a shot in the starting 11 straight away and was then injured until mid-March.
He missed 70% of the season (and spent time getting into form and shape outside of that time as well).
Then this season he was a starter, team hit a rut, his form dipped slightly, Valverde tried something else (with Arthur and Couts) and it worked.
And combined with his discipline issues (again, which are mentioned by a number of his teammates - you keep ignoring this) that's why he's in the doghouse now.
Noone hates him or anything of the sort.