Looms that are exposed get pulled on or bumped sooner or later, so yes. Would they survive without it? Maybe.
Ideally you dont want stress on the connection themselves, especially weight putting reversing torque on the screw heads. The vibrations will do their best to loosen a screw or two then. A crimp can't pull out if the stresses of an accidental yank are consentrated at a wire stay.
Look at how heavy outdoor ac lines get terminated. A guy line comes from high off the pole and has a cable stay to hold the main weight of the long line off of any electrical connections. Looped slack being on the runs side gives it a beter chance to slack out under extreme pressures (tie loops ONCE just enough to hold loops reasonably, two will hang up uncoiling), less chance of wire damage, you just have to re-coil/re-tie.
It's silly but the "real pigtail"(?) does garner smiles from folks that would never look twice at electrical too.
We'd be assessed by non-techs for general order, cleanliness, etc.. This touch was a secret weapon to draw a bored eye away from something minor missed (usually by assistants) ....surprise visit protection 
