Why rejection happens in interviews

Why  rejection happen in interviews
Any interviewer need to provider valid justification while selecting a candidate, but nothing while rejecting. It is a big mystery for candidates who will be rejected in interview after interview. MockInt team summarizes a list of 20 rejection reasons. Please note that this is list is apart from answering well in the interview.
1. Lack of courtesy and manners
2. Lazy
3. Non-punctual
4. Lack of a career plan
5. Dishonest
6. Over ambitious
7. Immaturity
8. Unrealistic aspirations
9. Scolding past organizations and bosses
10. Poor communication skills
11. Lack of sincerity
12. Lack of eye contact
13. Untidy or incomplete bio-data
14. No real interest in the job or the organization
15. Lack of knowledge
16. Lack of past achievements
17. Over aggressive and flashy
18. More emphasis on academics without experience
19. Extreme ideas and values
20. Disorganized answers
21. Asks no questions about the job
22. Unpressed and dirty clothes