Richard's callousness in the remainder of the scene also demonstrates to us his inherent weaknesses as a ruler. His plan to go overseas to Ireland while taxing the English and renting out English land shows us a typical Shakespearean flaw in kings: a willingness to ignore one's duty to the country in favor of one's personal interests. A king who focuses on anything other than the government of his kingdom--be it foreign affairs, scholarship, worldly pleasures, or his own self-aggrandizement--is bound to be overthrown. Richard clearly should not be leaving England at such a turbulent time, but his eagerness to wage war in Ireland and his astounding blindness to the precariousness of his position cause him to depart. Leaving for foreign shores will be his final downfall--by the time Richard returns, he will already have effectively lost England to Bolingbroke.
Finally, Richard's callous remarks about John of Gaunt's illness indicate his lack of respect for anyone besides himself--including the elders of his own family. This self-centeredness will help lead to his downfall.