Question

why do boiled seeds fail to sprout ?

Answer 1

Boiling denatures or harms certain chemicals or proteins which are required for germination so the bubbled seeds neglect to grow. 
Growing seed will have building squares of life called proteins. This will help the plant to develop. In any case, at high temp, the protein free its structure because of denaturation. Accordingly, the bubbled seed can't develop into the plant when it is bubbled. 
Also, on the grounds that you executed the seed. Temperatures over around 140 degrees F unwinds the proteins inside the DNA and hence executes the hereditary material