Pretty much everyone with knowledge of mainstream (non-Austrian) economics came up with the idea of non-deflationary cryptocurrency (keynescoins) around 10 years ago. That's how you can tell that everyone who says "it's about payments/adoption/etc not speculation" is lying because why would they make it deflationary.
Also, fixed linear emission is pretty much the second worst possible monetary policy and I think it's basically a way to have plausibly deniable deflation. If Grin adoption follows an S-curve then 50%/year emission won't be noticeably different from 0%. (And if it doesn't follow an S-curve then it has failed anyway.)
Also, fixed linear emission is pretty much the second worst possible monetary policy and I think it's basically a way to have plausibly deniable deflation. If Grin adoption follows an S-curve then 50%/year emission won't be noticeably different from 0%. (And if it doesn't follow an S-curve then it has failed anyway.)