On paper, Rodolphus Lestrange was a captivating enough character. As sadistic as his wife, Bellatrix, and equally as loyal, Rodolphus rounded out Voldemort's more vicious rank of Death Eaters. However, even though he was the kind of dark wizard who would gladly go down with the shi
(as he more than happily proved when placed on trial for his crimes), his translation on screen wouldn't have added much to the bigger picture.
Firstly, having someone equal to Bellatrix in almost every way would have just taken away from Bellatrix's overall presence on screen. One psychopath was more than enough. Also, introducing her husband would have also taken away from her relationship with the Dark Lord himself. What's so fascinating about Helena Bonham Carter's portrayal of the character is how obsessively devout (and almost in love) she is. A husband would have just been a detractor.