Honestly (and I am not a retailer, so I have no monetary bias here), Kenmore (actually Whirlpool) is the only brand dryer I would personally buy. I see more problems with other brands than I do with Whirlpool/Kenmore machines.
Again, one likely cause of failure is heat build up from back to back loads. But, you may have gotten a lemon as well.
I would replace the motor and keep the dryer. That is actually a very good machine. Of course, it is always a good thing to buy something new. It keeps the wife happy!
Matt