Question about free teamplates!

Hello guys i am new as web development :) I know its a stupid question but there are some free teamplates out there that can be used even for commercial use,like "www.tooplate.com" . This means it gives you css and html for free to use, then u change some content and images and u ready to give on! So why dont every people use teamplates then recustomize them considering their customer's needS? instead the have to write whole code from begiing?