Mate laptimes don't mean nothing in the real world only on this site.
Laptimes do matter a lot in real life. But I see your point. When you're doing your normal driving you don't stretch your car to the limit that track driving can reach to. So what matters the most are things like torque, power, ride comfort etc. But when you're in market for a sports/performance car, it will matter for you if your sportscar actually can perform as such and don't get crushed at track by a diesel van.
You want to enjoy driving your sports/performance car and much about that drive-ability, handling performance and driving enjoyment reflects on laptimes.
So if laptimes only matter on this site (as you said) then all the magazine tests, tv show tests etc where they take timed laps were actually exclusively made only for this website! Well, unfortunately that's you know it's not true. Lap time is a huge selling point for any performance oriented vehicle and it is obvious for everybody, including media and car manufacturers and sales people.