It may be because due to cowardice or they may have other priorities, dont forget under under mms our economy was strong, though crude price was 100+ dollars able to sell petrol 60-70 Rs, employment etc. They failed in military sector, thats why we overthrown them, they got the price for their sin. As political party they have the right to question the government and government is bound to reply them, escaping from queries is a coward act.
I dont think not even bjp will tell congress is anti national.