I do think that most people give genuine advice. The problem is that everyone has their own favourite coins, and will recommend them. And often the reason that a coin is someone's favourite is that the price has gone up whilst they have held it. And obviously if a coin has risen substantially in the past, that is not a reliable indicator that it will rise again in future, or that now is a good time to buy in.
It does always come down to DYOR.
People think that the coin they are holding will be valuable in the future that's why when someone ask them what coin to buy, they would recommend the coin they hold to help others or just to boost the price. Nevertheless it would be to attract other people to buy their coin to have more volume. Many people choose their coin depending on their strategy may it be base on news or technical analysis or just recommendation from other people and the problem with having no basis why they bought it and just listened to others is that they would blame the people who recommended it to them.
Regret is part of this game. You can't always go by what some stranger recommends.
Unfortunately, sometimes it is the only way for others to learn because if they wouldn't experience it themselves then they would not listen to the advises. I always encounter the "Do your own research" but who actually do it are the one who was shilled a coin before and lose so they learned their lesson and I am guilty of this one too.