As for the topic at hand.

Most likely, they've been looking at different suggestions over the years, and the two biggest fanservice race suggestions were Viera and Ronso.
They wanted to do both, but only had plans for one more race.
They can't just keep adding races, the biggest resource drain with new races is remodelling all of the existing equipment, and all of the future equipment requiring an additional variant, it's an exponentially increasing workload.

Could there have been less backlash if they just went with Viera and never even mentioned anything remotely like Ronso? Probably.
That doesn't mean this decision was made out of spite against male Viera fans.