Do you know the reason they sold him that over any other gun? It’s not because it’s a good starter gun, it’s because they have a huge mark up on them from the supplier.
I know this because when we first started they recommended the ASG M15 to us for exactly the same reason.
For reference, a team mate of mine started with the Nuprol defender, first game it stripped a piston, sent it back for repair, second game the trigger mech went pop, back for repair, third game it locked up within 10 shots. Purchased from the same shop as you.
So yourself a favour at some point, try a G&G CM16 and see the difference in performance between yours and that, and then look at the price difference.
The reason its highly recommended is it’s been tried and tested, known to be reliable, and bloody good performance for a cheap gun.