Only items with motor over a set size and not part of an appliance need an isolator. What one must realise the regulations cover commercial as well as domestic and so much is left to the skill of person fitting the units, for example in my late mothers house there is a sub consumer unit next to back door in the kitchen covering whole of kitchen, so although the electrician provided a switched FCU for the hot plate, since to reach it you need to stretch across the hot plate, in real terms it's not required, one would use the RCBO in the consumer unit or switch off whole consumer unit specially as located on the exit route from the house.
So if I for example wired up 3 showers for workers to use before going home, I would be unlikely to have three separate isolators, likely the distribution board would be rather close, even if not likely one three phase isolator would be used for all three showers. The regulations have to allow for this, so they don't stipulate using an isolator.
However as said it does make common sense in many installations to have local isolation even if not required, but things do change, it was common at one time to fit isolators for washing machines away from the machine, but reasonably close so if the weights came loose and it starts to walk around the kitchen wrecking every thing it touches you can quickly and safely turn it off. However today most washing machines have an automatic switch off if unbalanced so today not really required any more.
As to isolator to make it easy to defrost freezer, it also means it can be accidental switched off, same goes for waiting for sister to get in shower, and hair die all over her hair then turning off the shower, or simply flushing the loo. No I didn't do it, but I know people who did. Isolators are not always a good thing!
