I agree actually - there is nothing better than the satisfaction you get when you find something major in the tree or break down a brick wall you have been facing. There is also nothing like finding old letters or photographs of the family. If it was all done for you - no one would bother as it would be boring!
Absolutely. I am so glad that I began this all (even as a very late comer) some 12 years ago, back when places like Ancestry were sources of records - not of canned family trees.
Now, when I type in a family member's name in a census search, for instance, I am presented with a list of all the records on the site (including sites that Ancestry has gobbled up, like findagrave) relating to that person ... many of which are only identified by Ancestry because of the extensive corrections and additions I have made to its records.

But it also points me to many unrelated records for people with similar details. (E.g.: a family in east London circa 1900 with the same unusual surname as mine, who managed to have half a dozen kids with the exact same names as my grandparent's siblings; the eldest sons, born the same year, with the same name, were both killed in WWI, etc.) Anybody who followed those trails would be sadly misled.
And then (I haven't read the whole thread yet, but I'm sure someone has mentioned it), what of all the idiot family trees? Like the one (actually, about 50 at Ancestry at any given time, and all over the web elsewhere) that has my Cornwall ancestors making a quick two-way trip across the Atlantic and having (and abandoning) a son in Tennessee in 1775... or the one with a distant Quaker rellie of mine in Pennsylvania whose grandson was 250 years older than him?
When it comes to other people's family trees,
https://en.wikipedia.org/wiki/Trust,_but_verifybut really: verify first.

One other quick comment: not everybody wants their family tree accessible to the world and its dog. I don't.
And speaking of the world - does Ancestry still have that One World Tree thing?
