Past discriminations can create modern hardships. Groups that faced hardships in the past have a harder time establishing themselves compared to those that did not have institutional racism against them. Take for example the issue of housing and how racist it was and went against minorities,
particularly African Americans. African Americans were not allowed to purchase housing in some communities because of their race, thus not allowing themselves to improve their life and move into a better community. White homeowners believed that living next to an African American would devalue their community and thus created Institutional placements to bare them from certain communities. Without leaving into better conditions African Americans were stuck in ghettos, or low income communities even if they had the means to leave them.
The problem with changing institutional racism is that they have been in place so long that some see it as part of the system. People become accustomed to the hurdles of institutions and see it as a part of everyday life. For the system to change their needs to be outright declaration that institutional racism exists and sometimes those in power would rather state it does not to maintain the status quo.