I think the problems are many-fold. From cost-cutting by the airlines to reduced pilot training.
I don’t think there’s any evidence of reduced pilot training. The media’s portrayal of “OMG iPads instead of training” are ignoring that there have always been notices and updates delivered as text material. I think it’s quite reasonable to say that pilots today are actually much better trained than in the past. Every crash where pilot error is a major factor, they’ve changed industry training. (For example, pilots are now trained in “cockpit resource management”, where every role in an emergency is predefined, so every crew member knows exactly what they’re responsibility is in that situation. Contrast that with the past, where multiple crashes resulted from emergencies where some critical flight duty was forgotten because everyone assumed someone else was doing it. Or because of conflicts of personality/seniority.) Similarly, we now train pilots for equipment failures that we didn’t in the past.
Pilot training is way different now than it used to be. In the old days, most airline pilots were former military pilots who had thousands of hours of airtime in real airplanes (bombers, transports, etc). Nowadays many airline pilots don't have military training.
I don’t think there’s ever been a time when
most airline pilots were former military. Commercial aviation grew in lockstep with military aviation, so there’s always been churn between the two worlds.
They learn to "fly" in simulators and have very little time flying real planes (if any) when they're hired by an airline.
Nonsense. First of all, simulators aren’t worthless, as you imply. They’re essential to training many emergency situations. But as Nusa said, you can’t get hired like that. You cannot get a pilot’s license on simulators, and you most certainly can’t get a common carrier license (license to fly for an airline) that way. You need to accrue lots and lots of flight time in real aircraft.
In some countries, like Switzerland, airlines do hire people one could
teeeechnically call “inexperienced pilots”, insofar as they have their own training programs, so they hire as trainees people who aren’t pilots at all — yet. But of course they’re not piloting passenger aircraft at that point.