This is the latest in a series (of indefinite length and regularity) of blog posts memorializing cancelled toys. Our figure today is Bandai's Mighty Morphin' Power Rangers Rita Repulsa.
Rita would have been part of the "Evil Space Aliens" part of the line, and was shown at Toy Fair '94 along with the rest of the first series (such as Eye Guy).
The toy was never produced and, this being the early '90s, there was never any comment from the company on why. Hopefully for some better reason than "girls don't sell." At least one customizer has produced a kit based on the prototype, but the real thing was never made. It took until 2011 for there to be a Rita Repulsa action figure, and until 2020 for there to be a good one.
If it makes you feel any better, I'm reasonably certain the reason it was never made is a combination of 'girls don't sell' and the odd idea a lot of Japanese companies had/have that 'kids don't want to buy toys of villains'.
For example, the Brave series (e.g. Gaogaigar) toylines generally only had toys of the heroes, and even now it's kind of rare for any villains to get a toy in something like Kamen Rider (unless it's an evil Rider like Shadowmoon or the Shocker Riders). Even with something like Ultraman, where lots of villains/monster/evil alien toys are sold, they tend to be the big 'classic' names like the space ninja Alien Baltan or the robot King Joe rather than ones unique to the currently airing show.
Judging by some news coverage of Toy Fair at the time the figure was shown off (1994), the Rita Repulsa figure was always intended as a limited release because the Power Rangers TV show was already preparing for the transition to Lord Zedd as the main villain. Of course, in the end, Rita's limited release was limited to zero.