Vajpayee knew how to respect the secular fundamentals of India. He kept both RSS and religious fanatics at arms length which prevented RSS from influencing policies.
Muudi on the other hand, is a home grown product of the RSS, poisoned by their ideology. He will do exactly what they say.
Anyone who wants India to be a super power knows that for a diverse country like India with numerous fault lines, you are suppose to bridge them instead of exploiting and further widening those faults. This was the main difference between Vajpayee ji and muudi.