You should check your facts before you post. Back in the dim and distant past, as you call it, airlines took mostly from the military, just as they did up through the end of the 20th century. Testifying before Congress in 2001, then-FAA Director of Flight Standards Service Nicholas Lacey said, "From World War II through the mid-90s, approximately 80 percent of major airline new hires were military trained. Today, civilian pilots make up approximately 60 percent of all pilots hired. Today, civilian pilots make up approximately 60 percent of all pilots hired." Maybe it was different before World War II, but back then, flight was a luxury and safety standards few and far between.
Those "from the ground up" training costs that you mention have to come from somewhere, and with airlines running precariously thin profit margins, they'll come from The military subsidized the cost of training the overwhelming majority of those who would be airline pilots. The current costs of learning to fly on one's own are exorbitant largely due to the regulatory, court, and insurance costs borne by small aircraft manufacturers. A Cessna 172P in 1981 started at about $34,000, about 5-6 times the cost of the average new car. Now, the cost of a new 172S is about $300,000, more than 10 times the cost of the average new car. Add increased fuel prices and you get far fewer people going for the initial outlay of $12K to $16K to get their private pilot's license, the next place that airlines start looking for candidates.
If airlines are to train them from the ground up, as you say, they're looking at outlays just in pilot training on the order of $175K, not including what it takes to set up all of the intermediate operations to get them up to Air Transport Pilot and the required 1500 hours. The end result is going to be either higher costs for the passengers, lower pay for the pilots, or both.
It may be better for safety, but it might not be so good for the industry.