Why do we insist
Perhaps a poor choice of phrase.
We don't. Some think they are better. A great number think they are more convenient. Some make a living at doing it; they try to hoodwink any beek, or potential beek, into thinking theirs are better than all the rest.
Personally, I have never insisted at all. Never bought-in a queen. Doubtless mine will be crosses with some of them, and not all are as good with one trait or another - or even several traits. Those traits that I don't want are lost from my gene pool (and others are imported from the local stocks, whatever they are).
Whatever some say re feisty queens - the genes came from somewhere and will be around somewhere else. In fact they probably came with imported queens!!
I rear a few queens and replace some of the 'naughty' ones, or the non-performers, or the less prolific egg-layers - or whatever - and go again (or just carry on , rather), rearing from a choice, of stock, that I make. I am content with that.
There was trouble this last season with 'all and sundry' attempting to do A/Ss too early in the season and running into mating problems in many parts of the Country. Yes, I had to split one colony early to avoid them swarming while I was away, but I waited until nearly June before I split for a batch of fresh queens and the weather was favourable for them to mate. So there is another reason for imports - the suppliers 'must have' early queens or they would go out of business.
I could go on, but the reasons are nearly all of the ilk 'the grass is always greener....' and the underlying reasons are availability and controlled breeding of traits - some of which, many beeks can do little about. There is no perfect bee; there is always a compromise somewhere; the advertised traits are always the better ones, not the downsides...etc, etc.
RAB