I think it’s a bit sad to start immediately after school on an airliner as a young pilot. It’s not very challenging and as fun as flying in the bush for example with twin old pistons from the 60th/70th or Cessna Caravan where you land on place you won’t even believe it’s a runway. It really builds your confidence. Flying on your own with basically no rule, multiple different aircraft at the same time, with no paperwork whatsoever except the techlog and no QAR was kinda dangerous, but as a young pilot it’s so much fun. I’m flying Airbus for 5 years now and I really love it. Don’t get me wrong, there are other challenges and satisfaction but I do miss sometimes the freedom of real flying, single crew operation and adrenaline that you never get in airliner.
Saying that I fly with a lot of guys who only flew ATR or Jet before and most of them are very good pilots. For a safety point of view I don’t think it’s an issue as long as they are properly trained and their company allows them to fly raw data.