You are rewriting history, brother - viruses have been claimed to exist way before 1930s and peoples forced to use mandated medicine against them. What is unscientific about demanding to be shown proof of existence of something you are using to scare people into accepting mass medicating as a viable remedy? Your argument about isolation is moot - there's the scientific method and also some good postulates which can be used for proving existence, and then there's fraud. The "spanish" vaccine adverse pandemic a hundred years ago is a great example of the entire nonsense field. So deadly, yet so impossible to infect healthy subjects when tried in experimental settings.
Modern genome gymnastics are more proof of the century long scam of virology. Finding everything in a soup of cell debris and then using computers to create a sequence from it which corellates to a sequence in a government approved gene bank is not science. You can look up Lanka's experiment and see that he has recreated virus particles the same as ones claimed by "isolations", by simply poisoning and starving cell cultures without mixing an infected sample.
Making people sick is a very lucrative biz, though, especially when you socialize your operating expenses.