It is not pilot training. The root problem is that Boeing and Airbus are currently retrofitting larger engines into old airframes at the cost of pitch stability, when what they should be doing if safety was their primary concern is change the airframe to accommodate the larger engines.
Boeing in particular was under pressure from the more fuel efficient Airbus A320neo, and they needed bigger engines (larger fans) to compete on fuel efficiency. Those large engines don't fit under the 737 airframe, but getting a new airframe approved is time-consuming. So Boeing placed the bigger engines more forward from the wing, resulting in flight instability and pitch-up.
Boeing tried to fix that problem with software, but, as became apparent recently, weren't very successful with it.
Boeing in particular was under pressure from the more fuel efficient Airbus A320neo, and they needed bigger engines (larger fans) to compete on fuel efficiency. Those large engines don't fit under the 737 airframe, but getting a new airframe approved is time-consuming. So Boeing placed the bigger engines more forward from the wing, resulting in flight instability and pitch-up.
Boeing tried to fix that problem with software, but, as became apparent recently, weren't very successful with it.