In the sciences you will encounter concepts, experiments, theories etc that range from extremely highly reliable, highly predictive, to ones that are rather less so.
X-ray crystallography, mass spectrometry, Newtonian mechanics/physics, wave and particle physics etc. If you believe any real scientist has much doubt about many of these things and their results, you're shooting in the dark. If you bring up any evidence or experiments contesting any of this stuff, you're discussion may be received politely, or perhaps not, but it will almost certainly not sway anyone, and would probably be laughed off the stage, like some a flat earther Ludite. On the other hand there are new theories, new experiments, new results that are in a grey area, where there is a lot of controversy. In these areas, scientists may behave as you suggest, reserving opinion until sufficient data has accumulated, and a sufficient theoretical framework that has some predictive capability has emerged.
The point is, that scientist have some opinions that are rather unshakable and rock solid, and are not as reserved as you believe they ought to be, while in other grey areas they will be. In other words, some experiences are capable of engendering rock solid opinions, because they have massive predictive ability.
...and from another thread
With this, you have skewered your credibility.Originally Posted by Crocodile