As has been pointed out many times already, the problem is that sportives and races are very different beasts, and sportive organisers are often deliberately woolly about the distinction, despite the small print stating “this is not a race”.
Races have to satisfy a number of requirements which sportives circumvent by classifying themselves as “timed challenges” (e.g. restricted fields, specific insurance, police approval, race specific risk assessment, marshalls, commissaires, lead cars, etc).
There’s nothing wrong with Sportives per se, but a lot of hard work has gone into maintaining the right to race in the UK, and there’s a risk of compromising that if you blur the distinction between competitive and non competitive events.
Also interesting to note there is of course no requirement for drug testing in UK Sportives. A couple of riders in the US Grand Fondo were actually busted for EPO, because it was part of the UCI world sportive series, and therefore subject to testing.