Such thinking comes from a very limiting mindset which only considers one's own well-being, a self-centered way of thinking and living.
When the intellect is truly developed, then we can see the complete picture- we will not be a Dritirashtra who felt it was correct to wage a war with Pandavas, so his son could have the kingdom. If he would have utilized his intellect, he would have seen that- not only were Pandavas the rightful heirs to the throne, but Yudhistar also was better equipped to lead the nation.
Plus, Pandavas also had the kindness and etiquette to ensure that he and his sons were always well taken care of in the best possible way! Forget about being wise and deciding the best for his nation, if Dhritirashtra was truly smart (with proper discernment) he would have seen what was really good for himself (and his sons). But instead- Dhritirashtra chose to wage a war- which killed all his sons and he needed to retire to the forests!
Such anecdotes from the Vedic scriptures are not meant to simply convey history or tell a story, but it is meant to make us think. We should utilize the wisdom from such scriptures to improve our lives.
We need to focus on sharpening our intellect and developing our discerning power called 'vivek' in Sanskrit.