Based on what? (I'm guessing an uneducated opinion) Some of the finest homes ever built have metal roofs. Copper being the best choice due to extended life expectancy. Metal roofs, when installed correctly, and roof structure is vented properly is more secure, more weather resistant, longer lasting, and some say better looking.
After a lifetime in the building industry, and seeing the long term effects of quality metal roofs vs the relatively short lifespan of shingled roofs, I wouldn't put shingles on a dog house, much less a home that is the largest single investment most people ever make in their life.