Utilities should, of course, be priced at the cost to generate, maintain, and distribute the resource. But this is America, home of rampant capitalism. Thus, profit is king. That means utility prices depend on supply and demand.
Data centers use so much power that it creates a resource scarcity. So the utility company raises the price per unit that electricity is sold for in those markets.
Everyone's bill goes up when data centers are allowed in and shareholder profits skyrocket. Since the shareholders are happy, the powers that be are usually unwilling to address the problem as it is only the peons suffering.
It's actuality a little surprising that the government is trying to address the problem in this case.

Wouldn't it be cheaper in the long run to just put solar panels all over the buildings and parking lots, and maybe some surrounding fields, and an array of batteries to run off of at night? Maybe add some wind mills too, seeing as Texas generates a tremendous amount of power with wind already.