Because myocarditis is generally minor and often asymptomatic? It’s overblown here because it’s related to vaccines. Nevermind that anything from the common cold to penicillin to alcohol can cause myocarditis.
Go see for yourself at the Myocarditis Foundation: https://www.myocarditisfoundation.org/research-and-grants/faqs/causes-of-myocarditis/
In extremely rare instances, myocarditis can lead to more severe outcomes (including sudden cardiac arrest and death), but that’s so exceedingly rare compared to the number of cases where it shows no symptoms or shows minor symptoms that resolve on their own with simple rest. The Myocarditis Foundation has a lot of information around all of this. They even have a post specifically about Myocarditis and the COVID-19 vaccines: https://www.myocarditisfoundation.org/myocarditis-and-pericarditis-following-mrna-covid-19-vaccination/
Am I the only one who knows about the Coxsackie B virus that infects about 10,000 people in the U.S.A. annually? Coxsackie B virus usually affects the heart, lungs, pancreas and liver. It causes Bornholm disease, hepatitis, myocarditis and pericarditis. It is spread through fecal contamination.