I think Nintendo did not want females to be wearing bloomers because they were actually more skimpy than the short shorts worn in the Mario Strikers series.
For your information, the below image has Samus, Peach and Daisy wearing sports bras and crop tops with short shorts.
And this is what female volleyball players wear in the NES/Famicom Disk System version of Volleyball:
Just look at the pair of shorts she is wearing. The pair of bloomers she is wearing looks more like a pair of panties.
Would you want to have female characters wear shorts that look like panties if they are wearing sports bras or crop tops as well?
Nintendo games and characters © Nintendo.