In the interests of balance, here's a right of reply from someone who got taken to the "English seaside" as a child.
Devon and Cornwall can be superb
(though I rarely bother with the south coastlines)
I have dismal memories of days at Littlehampton and other "beaches" along the Channel.
I don't think anyone should base their opinions of English beaches soley on these
(the sea is usually grey, rarely much sand and almost never any decent waves)
John Geert's photograph sums-up perfectly my memories of seaside holidays in England: sharp shingle beaches, choppy sea and warm clothing against a freezing wind off the English Channel.
Here's some Bottlenose Dolphins I was watching on the West coast of Wales yesterday
D500 300mm PF plus TC1.4