??
My reactions 60 years ago (when I was slightly younger) would have been the same as now.
Some people are open, some people are cautiously open, some people are Just cautious, some are closed. Been like since before dirt...
-Chris
What people are unfairly doing and then using to attack the forum and it's members is they're comparing two very different situations. You can't compare posting on a forum to walking up to someone in person. They are not the same. In person, one can quickly judge and form some opinions based on what they see, hear, and smell. You can have a conversation with lots of interaction.
Online, hardened criminals can sound like the sweetest person ever. This isn't the tourist center lunch bar. People from here who have met have had great times together, but they initially met either with a group or in a very controlled way.
Each person here has their reasons and several of us tried to offer the OP suggestions as to a workable approach. If it was just me on my boat, I might even react differently, although offering to take a stranger is likely something I'd never do. If I met one at a marina and got to know them there though I would. However, we often have other guests and I have a responsibility to them too. I'm not going to spring someone on them I don't even know.
And if one wants to think no problems from boat forums, then please rethink that. Not as bad as facebook and not as scary as tinder. But just look at the Uber issues of safety with violence by passengers and by drivers. I know of a case where someone met a boater trying to sell a boat, or so he thought, and he was robbed and tied up and left and not found for a day. I also know on one of the most prestigious boating forums of a ship and boat owner from Europe who "hired" a US captain. The US captain dropped what he was doing and prepared for he and his wife to move to Europe. From that point the two stories are extremely different, but needless to say the captain was left unemployed and nearly bankrupt.
I believe 99.5% of those on this forum are trustworthy. There are many long time members I'd be extremely comfortable with because of how much I know about them. I'm sure the moderators and administrators could tell you of a few scammers over the years. I've been sent a prospectus of an oil venture (fracking) from a member of a boating forum who I wouldn't have trusted an inch.
I don't go looking for people to give boat rides too. Yesterday, we already had 13 aboard, all who knew each other well. When cruising I don't look to add friends, since the people we see, we're not likely to see again. However, I have embraced many people we met along the way.
I'd give the same advice to meeting those from a forum I give to those on dating sites. Talk to them online until comfortable, then on the phone. If comfortable, exchange identifying and verifiable information. Then meet for coffee or lunch in a very public place after telling someone you're doing so. Now, you can get to know them. Still no guarantees but you greatly improved the odds.
Oh and I know a lady on a sailing site who met someone from it. The lady was an experienced sailor and looking for a platonic sailing experience. Everything was discussed and agreed to. Then the first night of the trip she's asleep and he crawls on top of her. After she maced him, they returned to their starting point.
We are the most private people here, or among such. I was always private, but an even 18 years ago forced us to be highly secretive and private at that time and for years to come. You don't put photos online when you're told your life may depend on it. We're beyond the threat now or 99.9% beyond, but habits stay with you.