I agree.
There is so much goofy unexplainable shit in TMNT, so it seems weird that people take issue with the rat version of Splinter.
We're okay with aliens, mutated animals, and ninjas with giant shells on their backs... but we're going to draw the line at a rat learning martial arts?
Whenever "logical explanations" are shoehorned into obviously goofy stories, it just ruins it.
It's like how Mutant Mayhem showed the turtles stealing because I guess we desperately needed to answer the question "how do the turtles get food!" It's fucking retarded. No other iteration felt the need to work in an explanation for this. There was no explanation for how Mikey got money for pizza in the 1990 movie. Because there didn't need to be. The entire premise is silly on its face, so there's no need to go into these weird explanations.
On the flip side of that, I'm okay with people liking Hamato Yoshi as Splinter if it's just a personal preference or whatever. There are a lot of fans of '87 and 2012 TMNT, and those fans are just more familiar with and more comfortable with Hamato Yoshi as Splinter. I guess I can understand that. I really only take issue with it if their reasoning is just "rat Splinter doesn't make sense"