This reminds me of the super old joke "iPod, iPad, iPaid"

The i-line of products was already well known by the general public at the time to be synonymous with Apple. iTunes, iPod, iPhone ... those were normal english words prefixed with an "i". People wonder why Apple didn't call their watch the iWatch. This is a much different thing with "mastrodon". It's not a word people are familiar with, has enough syllables to sound funny, and gets combined with other nonsense words people aren't familiar with. Compare that with something like youtube subscribers, posters, tweets, etc. which are all basic words. Mastrodon's situation is that it reeks of being engineer designed. That's not a good thing if your goal is to reach a mainstream audience.

The Wii did fine too.

iBrator

https://www.youtube.com/watch?v=i4-ReZh0sQw

"pad" without the "i" was already accepted as a term for something you write on e.g., "pen and pad"

I'm pretty confident that you can ask someone for a pad for writing, without thinking at all about hygiene products, but you can't even hear the toot of a horn without thinking of a fart.