Freebitco had a large audience because it was one of the most popular websites among other crypto websites, it was also one of the most promoted. I remember when one of the biggest bank in my country started accepting of Bitcoin through a sister company, they were promoting Freebitco.in as one of the best ways to collect your first Bitcoins.
Even with all the recent issues with freebitco, they still have more than 20M hits per month. Still, many gamblers prefer to gamble there or some may even come there only to claim free faucets but this traffic number is kind of huge especially when you see the complaints and issues faced by gamblers on this platform.
Btw I wouldn't say that users had the opportunity to easily collect lots of sats because Bitcoin's price was low and if someone was working a job with minimum pay, would easily be able to collect lots of Bitcoins.
Mostly people who collected bitcoins through faucets may have sold their sats already but if someone only claimed the faucets regularly since few years, by now he must have accumulated a lot of satoshi's and considering the price of Bitcoin over a 100K now, he must be rich only by faucets but that vision and to not sell those free money, isn't something common. Most people will sell the free stuff quickly.
There is no doubt over your opinion as many who claim free coins likely to sell off without the thought of holding, I believe too well that the case of selling off free claimed coin mostly this days that allot of information and eye opener on how a coin can rise has made many to think towards holding without rush if selling, though some person without vision and who only target is to sell off any coin or investment they made in crypto or Bitcoin will always do no matter the level of information or awareness been created. The choice to claim free and hold is always advantageous to who ever that could practice it as best option in the ecosystem of crypto.