I'm not sure it is easier to do the work with machines. In fact I am sure it is harder. I'm years into the hobby end of it, and still have trouble with my milling setup. While any time I have used a file it has been easy. I built a machine to speed up rack joints, but it turned out to be still faster to file the joints with a rat tail. I have 30-40 years of woodworking behind me cabinets, guitars, boats. So my hand eye coordination is dialed in. The thing about machines is that they could be set up if enough dough, space, and iron was put into it, so that any wage monkey off the street could be making parts pretty much right away. But to turn out your first part, you would be done the bike before you had made a contact on Kijiji for a mill. It is a long haul before you get it home, get it cleaned up installed, leveled, working, and then get the fixtures for it and get it cutting reliably. And if you don't leave it all set-up so the mill is unusable for other stuff, it is a big job to get ti back dead nuts, and requires a little bit of knowledge if you aren't just a square it with a square guy. Mills are do anything machines, but it is fair to say they weren't intended for coping so there are a few bugs in that process. I'm not a framebuilder, so I do lots of other stuff on my mill, and getting the fixtures plug and play, the way I want them has been a long and expensive process relatively.
BikeFriday has a rule where everyone who works there has to make a bike so they really get what the company is all about. Their bikes involve both TIG and brazing, so it is a serious endeavor. I guess most everyone gets it done. But there is a whole mountain of difference between teaching yourself, tig welding say. And being dropped into the perfect setting and told to operate the pre-set machine under an expert's guidance. While you only need to be a one trick pony to cut a tube on a mill, you are nonetheless in mill operation taking up a whole hobby in itself. There is a whole hobby in knowing the rules for safe operation of an OA torch. This game is a lot of relatively easy hobbies, kinda stacked to the sky. The very first cope I did on a mill was perfect, but getting my mill to become fast without an indicated-in set up for every cut, has consistently frustrated my attempts to do a low cost Mcguiver. I have done so much machining for that fixture it would have carried me though a lifetime of hand filing frames as a hobby.
Here is the vid I normally post to show how it can be done jigless, at least the main triangle. Some guy who had been to their shop said they also had a lot of fancy stuff like jigs, but that they could swing either way depending on the needs of the job. Where I go wrong as a minimal production hobby builder is when I see something like the Cinelli fork bending jig in the next segment, and decide I have to make it.
http://www.youtube.com/watch?v=TMA8X5pk2kI