you are compromising fuel economy and also your tyres life span for comfort ... research a bit on the net you will find the reasons.
IMHO i also don't agree with the load on shock obsorbing argument. Shock absorbing is their "job" that is what they are made for and when they get hard after time they can be serviced and made soft again. not the case with tyres 
about comfort, I don't feel any discomfort in my car , infact City chalanay wala dost ne jab drive ki to kehta ye bohat ziada comfortable hai. But comfort is a relative term so , to each his own 