Any reason of my website denied?

Dont know if this helps - but whould share you my expierience - If I register on a new Advertising Network I remove the ADS I dont need/whould change (so that there are free ad space(s)) - OK the page looks than not complete for a while *loL* cause a banner is missing - but if the "auditor" visits your site and see - wow, there are only decent 3-4 ads and a nice space for my advertisers free .. that site can be accepted .
The user 5ub_zer0 has given you a great answer.
Usually when a site has too many ads from too many different ad network it will be rejected as our ads have a small chance to be seen by an user.
Regards.