Colt, civilian crews are in huge organisations compared with small air force units. They don't live in each other's pockets, socialise off duty as a general rule of even necessarily know by sight all the others.
Perhaps in the post-war golden age with navigators, radio operators, engineers, and a cabin staff, with one crew flying multiple stages then the crew would be 'constituted' . Neville Schute wrote a novel on that basis, DC6 or similar aircraft.
All true but what has changed with the budget airlines now on the scene is that night stops when crew members can socialise are a rarity. When I flew for the charter airlines in the 1980/1990s quite often you'd do a couple of night stops flying the W pattern at hotels where even crews from other flights were staying.
Compare this now with typically 5 on, 3/4 off pattern varying between earlies and lates and wanting to recover on days off and/or crew members going home from a remote base to family on days off there is also little interaction. In my experience even when there was the occasional "do" at base (e.g. Christmas) those on earlies next day could not attend, those on lates were probably too tired to turn up at circa midnight when the party was almost over and many others would be in another country spending days off with family.
Also much of the communication to/from the Company is now via email/web etc or by phone to some roster clerk the other side of the Irish Sea who you had never met.
The hectic nature of the flying with short sectors and rapid turnarounds leaves little time for getting to know your fellow crew member other than in an operating capacity.
All these factors can compound the feeling of being isolated and merely a "worker drone in the collective" encapsulated in Charles Handy's book "The Empty Raincoat".