Summary:
The reason for the sinking support of Prime Minister Shinzo Abe is his lack of leadership. The top reasons given in recent surveys for not supporting the prime minister were "the premier shows no leadership" (34.8%, Kyodo),and "cannot expect anything" from Abe (22.3%, Jiji)
　　　　The real fault lies with the irresponsibility and absurdity of former Prime Minister Junichiro Koizumi, the Liberal Democratic Party and the New Komeito Party for picking a leader such as Abe, who is lacking in maturity and ability.

"A swallow or a sparrow doesn't know the will of a swan."? from Records of the Grand Historian, a recounting of Chinese history by Sima Qian In other words, a dull-witted person can't understand the will of a great man. A swallow or a sparrow is a small bird, while a swan is a grand bird. A nation that puts a small man in a high position meant for someone bigger is bound to bring unhappiness to its citizenry.

Article:
Support for Abe's cabinet is sliding steadily downhill.
　　　　In a public opinion poll conducted by Kyodo News in March, Abe's support rate was 39.9%. This was the first time support had dipped below 40% in a Kyodo poll since the Abe government was ushered into power. Moreover, the No. 1 reason for supporting Abe was "there's no one suitable to replace him." This is a truly miserable position to be in.
　　　　A public opinion poll conducted in February by Jiji Press yielded the following results:
　　　　1) The No. 1 reason for supporting the Abe Cabinet (multiple answers allowed) was "there's no one suitable to replace him" (12.5%). Next, was "I trust the prime minister" (9.9%, down from 10.8% in the previous poll), followed by "he makes a good impression" (8.6%, down from 12.3%). Those who said the prime minister "shows leadership" totaled a miniscule 1.7%.
　　　　2) The No. 1 reason for not supporting the Abe Cabinet (also with multiple answers) was "I have no hope for positive results" (22.3%). That's a 5.1-percentage-point jump from the previous poll's 17.2%. Next was "he shows no leadership" (17.1%, more than 5 points higher than the previous 12.0%); followed by "his policies are useless" (11.1%, up from 9.2%); and "I can't trust him" (7.8%, up from 6.8%) ...
　　　　In the six months since the Abe Cabinet came to power, its support has been steadily evaporating and its detractors have been getting steadily louder. The main reasons for this are the irresponsibility of the LDP and New Komeito politicians who chose this immature, incapable and indiscriminating man, Shinzo Abe, to be Japan's premier, followed by the cheerleading of the mass media and former Prime Minister Koizumi, which helped create the Abe Boom that swept our premier to power. The fact that the LDP and New Komeito selected this man to lead Japan is a huge mistake ? the people of this country deserve an apology.