I've always been irritated by how they wrote the Whitley character. By the time she and Dwayne got together, Whitley had really grown up a lot and wasn't as self absorbed as she was when we first met her. Once she and Dwayne were engaged, it's like they reverted her right back to season one. It's no wonder Dwyane was getting cold feet and willingly started noticing other "real" women. Then they broke up, and she was almost instantly back to "grown up" Whitley. Then, right back to being pampered when they married. The writers wasted the character of Whitley foolishly way too many times. That last season could have had her less whiny, and more as leader(even above Dwayne) if they writers had cared enough.
The ending to the series is exactly what I would have wanted for them all, but the entire season was sadly wasted on NBC's part.
Although I initially was focusing on her voice (the earlier seasons she was obviously Southern and her accent was acceptable, but later on, especially during the last season, it takes on a whiny sound...almost cartoonish), I do agree w/you that her character never matured and stayed as a mature person.
The writers had Dwayne mature in a consistent and believable way. And he remained that way.Whitley oscillated back and forth, to the point of being (IMHO) completely childlike in the end.
I think its because by season six ALL the characters had grown maturely that the writers needed to lean on someone to amp the comedy quotient. Thus season six Whitley became Lucy Riccardo. They did the same thing to Thelma on Amen and a couple other sitcoms in their last seasons.
When theres no more room in Hollywood, remakes shall walk the Earth.