the bit i can’t understand is why do barbel anglers have this fear of change is it a generational thing?
There's a presumption there that (a proportion of) anglers are afraid to change, with the inference that these anglers are of a different generation to yourself. Maybe this is true in the case of some anglers, but it's a bit too much of a sweeping statement IMO.
You state the two purposes of a rig (fooling the fish in the first place, then having anti-eject qualities) and they are inarguable. But only an idiot would change their rig if it was working successfully. That is, first establish you have a problem, then, and only then, try to fix it.
If one is fishing highly pressured, relatively narrow stretches of crystal clear water, containing few barbel which are large and have wised up/are ultra cautious, then you know before you make your first cast that you're up against it. You know that you need to think on. Experiment.
But to experiment with blowbacks, KD rigs, Ronnies, Chods, Zigs, Combis, Multi-rigs, Claws, Hinged stiff
ad infinitum when you're already hitting the vast majority of bites you get, equates to inventing problems you don't have. That is, only try to fix problems you know, or at least suspect, that you have.
I reckon that carpers are one of the (maybe) two most innovative and 'flexible' (open to change) anglers, the other group being match anglers. On many rivers match anglers depend on/need to catch barbel to win matches. Are they stuck in their ways, scared of change (especially those that are from a different generation from you)? Should they be experimenting with all those rigs listed above and more? No, they learn from each other and adapt to circumstances/conditions etc. That is, when they have a perceived problem they try to fix it ...not change 'for the sake of change'.
N.b.. as a bailiff I've extracted rigs consisting of 3oz in-line weights, lead core, and a bent hook. Yes, those type of rigs will catch carp, and yes, they will catch barbel, but just because they work on the angler's local carp puddle, do they really
need them on the Teme?