That's my biggest problem with the "I now have X problem after the vaccine" crowd; quick to blame the vaccine, but they never question whether it was the virus itself that caused it.
My dad is one of these people and it infuriates me to no end that he defaults to "vaccine bad" and not his irresponsible behavior during the height of the pandemic which caused him to get very sick from the virus itself. Nor the fact that he had a very visible lyme disease rash 20 years ago and refused to get treatment because "MDs bad". He's quick to blame his neurological disease on the covid vaccine though, so frustrating.