Who decided, and basing on what concepts, that switch construction (in many languages) has to be, like it is? Why do we have to use break in each statement? Why do we have to write something like this:

switch(a)
{
    case 1:
        result = 'one';
        break;
    case 2:
        result = 'two';
        break;
    default:
        result = 'not determined';
        break;
}

I've noticed this construction in PHP and JS, but there are probably many other languages that uses it.

If switch is an alternative of if, why we can't use the same construction for switch, as for if? I.e.:

switch(a)
{
    case 1:
    {
        result = 'one';
    }
    case 2:
    {
        result = 'two';
    }
    default:
    {
        result = 'not determined';
    }
}

It is said, that break prevents execution of a blocks following current one. But, does someone really run into situation, where there was any need for execution of current block and following ones? I didn't. For me, break is always there. In every block. In every code.