Football is a business and business seeks a market. St Louis is a dump on a downward trajectory. Keeping the team there is revenue lost every year. This may sound like St Louis bashing, probably because it is. St Louis city is a violent squalid ghetto of about 320,000 food stamp recipients. None of them are buying tickets. The greater metropolitan area is just shy of 3 million, but nobody wants to go near the stadium. It is murder capital USA, alternating with WDC, south Chicago, and Detroit. Last summer after a Cardinals game a feral simian indigenous nigtard shot and killed a dad, Christopher Senna, in a daylight robbery in the parking lot. Anybody going to a game knows that could be them, and cops are not lifting a finger out of fear of being prosecuted, sued, or fired - the "Ferguson Effect" writ large.
Will Los Angeles be different? The new stadium will be in Inglewood which has nice gated communities but is about half ghetto with high poverty, a ton of homeless and gangs driving high crime. It is "diverse" and "multicultural", for all you liberals. Certainly not perfect, but better than St Louis. And if people won't go to the new stadium for inadequate security, the television viewership will dwarf the Midwest. Lastly, all the St Louis fans will quickly transition to the Chiefs or Bears, so there is little downside.