The difference between Bitcoin and Gems?

I guess because the whole point is that user participation is translated into value so you need a coin that is exclusively earned through the app and not a coin that originated somewhere else.
BTC and Gems serve different target audiences within the ecosystem. 


Btc is aimed towards users with crypto background, who probably already own BTC and are familiar with it. These users will enjoy a convenient method to send btc to their contacts (ie. without typing addresses). Gems is aimed towards the common user who doesn’t have a crypto currency background.

- There is nothing like GetGems with Bitcoin, there is no Bitcoin Messenger with a reward value model, no advertising model where receivers get paid for viewing ads (actually no Messenger does that, getGems is the first), no group payments/group tipping in rooms up to 1000 users, no instant messaging webclient for desktop, no referral mechanism etc. and Gems cuurency is the central of all these actions, so they will have a real usecase and value as the network grows.