Iirc, Rowling wrote about Albus Severus that Harry named him like that in order to - I don't remember her wording, only the general meaning - sth like "giving Albus and Severus another chance for their names having good connotations".

And when it comes to naming children only after people important to one parent, not to both of them... it's still better than in the case of Anne Shirley and Gilbert Blythe's children - all of them (except neutral Joyce) are named after Anne's friends relatives and family members (sometimes after their surnames) or after herself (Nan) ;)