It's important to realize, from the history of science, that the public view of theories (and by public I mean the scientific community and the media who follow behind them) is often wrong, but science has a terrible record of doing mea culpa, in my opinion. Science is very good at saying "we are now right", but it doesn't like to focus on its past errors. I was blessed to have some professors who imparted to me the wonderful history of wrongness in chemistry. I'm also old enough to remember when ideas such as terrestrial impacts were mocked as religious garbage, and general relativity was still considered iffy. In my own field, the errors were less dramatic, but just as colorful. A famous chemist once mocked the idea of tetrahedral carbon bonding and its role in chirality as a hooker being brought into good society (it didn't help that the scientist advancing the idea wasn't from a "good" school). In another case, an essential answer in quantum chemistry went unnoticed for years, and an empirical result in Germany was doubted because the work was too elegant to be believed, and the result unexpected (in his case, it didn't help that he was a Jew and things were getting nasty in Germany). Science has flaws because science is done by people. If there is one thing I would impart to young scientists, that would be it.
Bigsly, I would say that no theory is ever on 100% solid ground. They all seem to have a boundary at which they don't operate at 100%. Everything breaks down at some point, and either gets help from other theory, or is a big fat question mark and requires upgrading or extension. But you are right - the few nasty players who diss the opposing views without respect or self-examination take the fun out of the game. I will always respect my former advisor for the fact that he would treat with honor even the least respected and most controversial scientists of his field - particularly those who opposed his own views. As it should be. Science is no longer a rich gentleman's pastime, but we can still be ladies and gentlemen.
It's all rather interesting, but I personally prefer being a bystander now!