imo a full revamp of the design team or Alex passing on the game to someone who cares might make it have some interesting updates.
If you look through suggestions there are loads of brilliant fun ideas that dont get added because they're too 'big and insignificant' which is code for we're too lazy.
Your hypothesis is very correct, as can be seen by the number of people that join the game vs the number that stay. The game has such good advertising yet so bad gameplay that;
6,730 nations have been active in the last week
1,460 new nations have been created this week
Meaning, more than a fifth of nations active within the last week were created this week. If even 20% of that stayed, we'd have a growing playerbase, but we simply dont.
TL;DR: Design team need to focus less on advertising, and more on creating fun gameplay for new players