I think Wolfman was planning on showing that it wouldn't work out.
"I don't usually talk about undone stories because some day they may get done. But yes, there was a Dick-Donna romance planned. Frankly, I would have left her married to her hubby because I still think Terry was the best match for her but since he was killed off without my imput, I did plan to later get the D-twins (Dick & Donna) together, if only for them to see that they were too similar to be together."