Unless your water company/local authority says otherwise, then drinking water from your kitchen tap - and often other taps in the house such as utility room - is safe to drink (and so shouldn't need boiling it to kill any germs). Who says it's wrong? They're crazy. I'm perfectly happy drinking tap water at home, and it's what I ask for at restaurants as it's free. However, when in different counties I sometimes prefer bottled water if I find the tap water different to home and not very nice, which can happen to me! Call me fussy, I don't know. But generally then drinking your tap water is the done thing surely!?! Otherwise people are wasting a lot of money on bottled water and being wasteful towards the environment also.
When abroad it is different, as many countries are not as lucky as us - their tap water may not be safe to drink so bottled water is the safe option in such situations.