That's true. But when you look at it in context, it's easy to see why. Even in western non religious countries, the vast majority of those people who leave Islam stay 'closeted' for a long time. This means pretending to be Muslim, ie. fasting, praying, wearing religious clothes etc This is particularly true for young atheist former muslims. They can't leave Islam alone, because Islam (or rather Muslims) won't leave them alone.
In Muslim majority countries, the issue is far more critical. For the vast majority of people there won't be able to ever comfortably 'out' themselves and will likely spend their entire life faking it, including marrying a Muslim etc etc
For both, the internet is virtually their only outlet for rants. When Muslims ease up on the issue, the atheists will ease up as a natural consequence.