Unless someone knows different

[ThrelfallYorky]

I can't understand quite why/how anyone would merely "name-collect". I've not thought about how many "names" are on my trees - and I suppose it's a bit of a distinction that NONE of them are famous - but I can get fascinated exploring siblings of direct lines, and parentage of spouses who have married in.
Often that can clarify why some odd name appears - it's a surname a few generations earlier, or something.
Also, sidelines can help - people apparently unrelated to the Householder, listed merely as "lodger" have some times turned out to be related, cousins, stepchildren, nephews, etc - even parents-in-law - so I tend to keep lots of index-cards of fairly well proved information.
I can't quite see, though, quite why people seem to "adopt" whole chunks of other people's trees. Just because it "looks possible" isn't research, is it? Even with trees I now know I'm linked with, I still prefer to hack through on my own - although I'm grateful for suggestions, and guidance from people on here, and delighted when they work out, to feel I've actually found it out and then checked it out as well as I can, before even thinking of setting it out as "Fact".
We've all ended up with "Wrong" certificates that fitted so well. Some people write that down to experience, and pick themselves up and start again.
Others can do wonderful convolutions to make facts fit - launching ancestors to the other end of the country ( with different birthplace, spouse and children) for one census, before apparently abandoning them to return home for the next! Perhaps this also can assist the "Ancestor-adders"?

[Erato]

"I can't understand ...."

As I said, it's because different people are interested in different things.  By way of analogy, many people collect shells [I'm one of them] but not all collections are the same.  Some people are very specialized and focus on absolutely perfect specimens of only one family; some have shells from only one place; some collect whatever they can get their hands on.  Some people have a scientific interest in the specimens; some look at them as natural art objects.  There's nothing wrong with one approach or another.  It is, after all, just a hobby.

[lizdb]

No there is nothing wrong with different appraoches.   The shell collecting comparison is good.

What is wrong (or at least to my mind) is when someone then presents their tree as fact, when it has not been researched at all, just names taken from someone elses because it seems to vaguely fit, or the only person that comes up on Familysearch with that name so it must be the right person.
And then peoples trees come up on research websites alongside original sources such as census returns and bmd registers and prs - and these days the only way (and certainly the easiest)  way to access these vital documents is via such websites. The line between fact (or at least survivng records from which to try to ascertain the facts) and fantasy (which some online trees are) is getting blurred.
To use the shell collecting comparison, it is like someone sharing their collection on a leading shell collecting website (if there is such a thing) and stating that this one is an x and this one is a y, etc, when it is totally erroneus. Some other person who has a lax approach and little knowledge and no desire to research ( and there is nothing wrong with that appraoch if that is how they want to do their shell collecting) thinks "Ive got one of them,it must be an x or a y" and then label their picture on the shell collectors website as such. A few more copy it.  And fact and fiction soon get blurred.

[ThrelfallYorky]

Lizdb, how much I agree.
The trees we sometimes see online that get us wanting to say " that can't be so, because..." often seem to be so much the result of sloppy research, not checking things out PROPERLY.
Online resources can be a great help and starting place, but - come on, some really don't seem to have checked anything about them out! I have seen real "howlers" - people living for 160 years, children "born" before their parents, etc. COPIED from one tree to another, without apparently being spotted!
With the original person, that may well have been a "mistype", but it's so obvious with later ones that slabs have merely been copied wholesale.
This sort of thing can lead people to compound their own errors, especially when we are starting out and eager to get that tree growing. And that can lead to frustration later, when you realise how you've grasped at a very wrong straw.
Perhaps there should be another term for these trees? I like your "Fantasy Trees". Perhaps we could all get back to Adam and Eve ( or even Lilith?) that way?

[Erato]

"Fantasy Trees"

Caveat emptor.