The context in which the reply was given was reduction of cable size from
6mm to 2.5mm this has to be fused down, there is a limit to the amount of
sockets on an unfused spur you cannot spur all the kitchen appliances onto a
single 2.5mm cable sorry if this was not clear.

Agreed - a single 2.5mmsq feeding many sockets, not-fused-down, where
the protective device is (say) a 32A MCB, is indeed a Bad Thing and
should Not Happen. But a 6mmsq "backbone", with short 2.5mmsq feeds
(unfused, connected via junction boxes say) to individual single or even
(though it's sillier) double sockets, would be compliant, though not a
Conventional Final Circuit. Each such single appliance-feeding socket
(a) would be protected against fault current by the upstream 32A MCB -
here the "short" feed is important to keep the earth loop imedance low,
so that operation of the MCB in the required 0.5s can be guaranteed, and
the temperature rise in this faulting cable can be kept within limits;
(b) would be incapable of producing an overload for the rating of the
short length of 2.5mmsq cable, since you can't pull a sustained 27A out
of a single socket (RefMeth1 rating of 2.5mmsq), hard to do so even out
of a double, and the actual connected load - single white-goods
appliance - will in fact pull no more than rating plate says, prolly 2kW
= 8A at peak water-heating time for a "modern" dishwash, possibly the
full 3kW = 12A for an older/fancier/faster water-heating appliance; (c)
closer-rated fault-current protection will be provided by the plug in't
fuse. It's actually a completely direct analogue of the "normal" unfused
spur in 2.5mmsq taken off a 32A 2.5mmsq-both-ways ring: the ring is
fused at higher than the rating of the spur cable, but the combination
of plugfuse and circuit-MCB provide fault protection for the spur cable,
while overload is "designed out" by fitting only one power take-off
point, either single or double socket.

Having said all that, and certain as I am that design calcs would
sanction such a layout in the right circs, I'd still shy away from
installing a circuit like that in an ordinary domestic setup: it's
simply too unintuitive for a subsequent householder or
inspecting/minor-worksing electrician to feel comfortable with. Having
had, in the previous house, a period of enthusiasm for FCUs with
directly-wired-in appliances, and then been inconvenienced when
repairers have needed to reliably disconnect the appliance or wheel in a
spare, I've come to appreciate the wisdom of the standard arrangement
with FCU to act as control switch for easy-to-operate isolation, feeding
a conventional 13A socket (unswitched for preference) at the back of the
appliance.

Stefek