Refusing to recognize epistemologies that don't suit you doesn't make those epistemologies any less useful.
My opinion on something never makes it more or less useful, but also I don't think anything could make critical theory less useful. And sort of comically, the inverse of your statement is very accurate. Epistemologies that prove themselves useful get my recognition. I subscribe to a pretty utilitarian form of epistemology. I freely acknowledge this is a statement of faith, but I believe the truth leads to good results, so any method of investigating what is truth that leads to bad results is likely very flawed. Critical race theory, if useful, would help us reach better understandings of racial issues that ultimately allow us to take better actions (the way you described critical theories real consequences, but that applies to all knowledge, and is not the direct activism pushed by the Frankfurt school that you don't care about even though that's entirely what's controversial here). Critical race theory instead stokes greater racial tensions and leads to spurious conclusions like "being on time is white" and "interstate roads are racial oppression". (Side note: both those statements are real things said by real people. Really white people at that.)
Beyond the absolutely giant need to unpack that statement, so what? Are you saying we should ban students from studying those lines of thought that lead to the French revolution because you judge the results to be politically inconvenient?
The Reign of Terror is not "politically inconvenient". Regardless, I don't think we should ban students from studying anything, which this bill doesn't do. I also don't think we should ban schools from teaching the thought processes in an academic sense, which this bill also doesn't do. I think it reasonable to ban schools from having students have to personally affirm those perspectives though. You can still teach what critical race theory is, you can still teach conclusions reach by people employing critical race theory, you just can't make a student answer that racism is power plus prejudice and therefore non-white people in America are never racist. And like, we teach the enlightenment perspectives, we teach the conclusions and outcomes drawn from the enlightenment, but we don't make students say that people outside of societies corrupting influence are "noble savages".
You're closer than you have ever been at this point to understanding what critical theory is. Think about it. How do you know what the limits of human knowledge are, and what are the implications of human knowledge having those limits?
The limits are practical limits. I'm not talking about things we can see but cannot comprehend. I'm talking about things we can't see. You're imagining an objective view of human society, but all humans are in society, and more importantly all humans are human. The practical limitation is that we can't not be human. The implication of that is that attempting to have an outside perspective is purely imaginary. If your theory requires such a perspective, you must acknowledge that your theory is purely imagined, and any connection to reality is coincidental.