Complicating that voyeuristic guilt is the fact that ASMR is expanding into the realm of literal pornography, by way of a whole genre known as ASMRotica. In ASMR's early days, some called videos intended to trigger the tingly feeling "whisper porn," much in the way that the internet designates exceptional shots of steak or the Sierras "food porn" or "Earth porn." ASMR enthusiasts were always quick to tell you that the feeling was NOT SEXUAL, but now that's not always the case, and some in the ASMR community are uncomfortable with how the whole endeavor will be stigmatized as a result.
Of course, if ASMR is just about getting tingles, then even without its being eroticized, it certainly can be considered porn-like. Following the Supreme Court's famous definition of porn as "I know it when I see it," ASMR can look NSFW. It's already the case that many of the most popular SFW ASMRtists happen to be young, good-looking women, and there's certainly something porny about watching internet videos by yourself to achieve an orgasm, of the brain or any other variety.