Why grow earlies?

I know the accepted norm is that if you can only grow one lot of spuds, grow earlies. But why? 

I am growing Elfe maincrop from Lidl and Charlotte earlies from B&M seed tatties. The Charlotte are rubbish this year (whether that's because of where I bought them from , I know not. Suffice to say I won't be buying seed tatties or onion sets from B&M any more.)

I digress, next year I will only grow maincrop spuds because even if you lift them early, at the same time you would lift earlies you get a decent tasty crop of new potatoes. The bonus is the longer you leave them the bigger the crop will be so you have the best of both worlds.

As an aside Jersey Royals are a maincrop  International Kidney, just lifted early. If left to mature JR's make huge maincrop potatoes.

 No so  called earlies for me next year just mains.

Hmmm, that's very good point you are making x

we get buggered by blight every year so quickest in and out is the way - not sure if main crop spuds would develop fast enough

not that ever get any decent spuds anyway

slugs, blight, etc etc