Public doesn't have the same love on forums, but I ride the TTC at least 3 or 4 days a week, and I have seen nearly a dozen people with Public phones. They are likely popular with low-income or specially targeted users, many of which may not be savvy on internet sources such as this. Public transportation is more common among those not looking to blow hundreds on car + maintenance + parking + gas + insurance, so the fact I see Public phones on Public transportation? lol.
P.S. Their website is back up. It could have been down for many reasons -- to recycle a server, to do an update, to rebuild some CSS, it may have crashed, etc.