This is a great idea...but there's so many restrictions.
I'm not sure what the taxes are like in these countries but the pass credits only cover base fare. You have to book 14 days in advance. No guaranteed availability. No do-overs? Kind of a bummer. When I read this the first time I was like "i don't even live there, but if it's good for 3-4 years I'll buy one right now". But I was bummed to see some routes were 3 credits as well as all the other restrictions.
If you're a backpacker planning a month long trip, this is great, cost certainty and you could book all your flights now and hop and jump all over. But for most other people, I kinda don't think so. Who needs to travel this much in a month and not repeat the same destination? Who needs to travel this much and none of it last minute?