And you base that on what? I'm not focused on headlines, what I'm saying is the result of most research on the topic, see (just examples):
Baade, R. A., & Matheson, V. A. (2004). The Quest for the Cup: Assessing the Economic Impact of the World Cup. Regional Studies, 38(4), 343-354.
Lee, C. K., & Taylor, T. (2005). Critical reflections on the economic impact assessment of a mega-event: the case of 2002 FIFA World Cup. Tourism management, 26(4), 595-603.
Maennig, W., & Du Plessis, S. (2007). World Cup 2010: South African economic perspectives and policy challenges informed by the experience of Germany 2006. Contemporary economic policy, 25(4), 578-590.
You're just repeating the old myths that FIFA representatives, officials and politicians repeat: Trickle down economics, infrastructure, prestige, tourism, blabla.
Don't get me wrong, I'm not opposed to give the world cup to developing countries and I'm in favor of a change from the western-centric focus on sports. Just don't do it the FIFA way.