Bitcoin is an online currency. Even if started with a lower price. Now its value is beyond the reach of ordinary people. But, nowadays, it seems that Bitcoin is losing its popularity.Because, not receiving validity in low income countries. It may be the main reason.
You can only say that bitcoins was on a decrease in popularity if there is a drastic change in bitcoin users worldwide and you should be backed up with statistics.If you are observing the current condition of bitcoin were as of now maybe you can tell if it is declining in popularity. Moreover, not all "low income country" you are saying were against implementing bitcoins if you search for countries accepting it.