Why has Pakistan put 4,300 beggars on no-fly list?

Pakistan has placed around 4,300 beggars on the Exit Control List to prevent them from flying out of the country. This comes after Middle Eastern countries threatened Pakistan with strict action if they didn't stop "exporting" beggars. In September, Saudi Arabia had told Pakistan to stop its nationals from misusing Umrah and Hajj visas to reach Saudi and beg.