Please allow for the possibility that the word "secure" is no more than an attempt by a company (Microsoft) to leverage your fears and co-opt your natural pursuit of safety in order to help make a consumer-restricting technology appear to be a feature. Would you have as much faith in the technology under a different name? Perhaps: MicrosoftBoot (implying it could only boot a Microsoft OS, or the specific version of Windows your PC came with)?

(In a sense, dropping TLS is the correct response... In the sense, of not using the limited set of services. The corresponding response here is to not buy PCs with SecureBoot present in any imposing way, which may mean boycotting "modern" computers that are no longer general, user-controlled, devices if, in the future, they all are locked to Microsoft out of the box.)