Roseanne is the first Jennifer I was introduced to. I was surprised when I finally saw what the original actress looked like, and how tame and docile her character was.
It was an odd way to reinvent the character. Also Jennifer's physical changes in 94 were written into the script, so it just ended up making cruel fun of Roseanne's looks.
I prefer the Jennifer recast from 2015.
But to be honest, the original Jennifer from the 80s was an AWFUL actress. So it was probably pretty easy to totally redo the character. There wasn't really anything to her back then.