Jet2 self handle their own operation to make sure they can have the right degree of control, as soon as they start to handle another carrier, those reigns loosen and the focus on Jet2 ops slips. Depends if they see it as a a cost centre (which it really is) or a profit centre (which it's not). The only killing made in ground handling is to terms and conditions.
Completely agree, Just that if Jet2 were aiming to expand further, as long as their own operations weren't compromised, they could look into a few extra's.
Particularly on the down times, between the first and second waves, utilising their operation more effiently, with no to minimal impact on their own flights