Who in all of Nintendo's offices would even think of getting rid of the Goombas?
What would be achieved by no longer using the Goombas?
When would they start getting rid of them?
Where would anyone get the idea that they would get rid of the Goombas?
and most importantly
Why? Just why would you even ask this in the first place?
No. Every game need to have an easy enemy so that new players can jump right in. And they can be difficult sometimes. Para-Goombas, SM3DW Octogoombas, Spiked Goomba, the list goes on.