As to not being respectful to sincere Catholics -- I would to some extent agree, but state that unless the deceased really went against Church teaching (like Kennedy, T), I, personally, would not be offended.
The best thing those who lose a loved one can do is to avoid hurting others who survive the loved one by waking up all those sleeping dogs they tiptoed around for years.
I tried to persuade my brother to have a very quiet Mass with just him, my other brother, me, and our spouses with a quiet interment at the cemetery, and then invite the extended family for a luncheon and a reunion.
I know that the Mass would have been very comforting for my Catholic brother and he seemed to need this ceremony, but I did not think it was appropriate or respectful to subject the believing and practicing Catholics among the extended family and friends to a religious spectacle celebrating the life of an **avowed** , unrepentant, and open atheist, and an unrepentant and openly non-practicing Catholic.
Honestly,...I don't think this is what my parents would have wanted. Given that extended family and friends knew my parents standing with the Catholic Church, I believe they attended only to be polite to my brother.