Tire Blowout problems of the 2000 Mazda MPV

Both front tires (inside edge) worn out around half the circumference of the tire. The front tires worn out prematurely with the treads showing separations about an inch long from edges where treads meet the sidewall. The steel belts could be seen from the one-inch separation. Car dealer service manager could not figure out what caused the premature wear. . The vehicle tires have been rotated and balanced according to maintenance schedule. Contacted tire manufacturer and referred to a local dunlop dealer. Tire dealer concluded that tires were not rotated. My brother- in- laws Mpv 2000 with 25k miles experienced the same tire wear (the brand of tires he had was yokohama), but much more severe damage with longer tread separation causing the tires to lose most of the air. My comment is, could this be a car problem (suspension), and not the tire? I am thankful that these tires did not blow up at high speeds. Who knows how many more out there are not being reported. Thank you for taking the time to read about my problem and hope to hear from the NHTSA soon.