I dun mean that individual taste should be killed but at least there should be some decent standards like in controlling the blown highlights, shadows, a lil decent contrast, decent saturation for the norms...
Who decides what decent standards are? You can set technical standards (e.g. clipped highlights, but technical standards don't say much about the artistic merit), but contrast and saturation? Looking at a lot of "nice" pictures and the "hope you don't mind, I took your photo and posted an improved version" posts on Clubsnap, it appears that the local taste emphasizes stark contrast over blown out highlights, and Walt-Disney/Technicolor-like kitsch colours over natural rendition. To my eyes, more often than not acceptable pictures get "improved" to eye-stabbing monstrosities that should be banned by the Geneva convention.
And there are discussions about "over- and underexposed" pictures if viewers would prefer a darker or lighter version, or if they look at the picture surrounded by a glaring bright or a dark screen background. (Honestly, the Clubsnap colour scheme for viewing posts/the gallery is a poor choice for looking at pictures, but the admins don't even bother to reply to politely formulated feedback.)
Different viewers should naturally have a set of different views. Although there's a very noticeable Lemming mentality: pictures get little to no comment, until someone starts the ball rolling: "this is to bright/dark/badly framed/etc, and I would do this", and all of a sudden there are numerous posts regurgitating the very same thing over and over again, especially if the first comment came from one of the better-known Clubsnappers with some perceived authority. And all of a sudden, there's a "standard" because everyone agrees with the naked emperor instead of using their own brain to form their own opinions.
What I want to say is, we should at least be able to know how to get the right effect first
The only "effect" that can somehow be argued to be "right" is the colorimetrically and photometrically accurate reproduction of a scene. This automatically excludes any contrast and saturation manipulations, white balancing, etc. and will most time result in pictures that cannot be reproduced in print or on screen. Strangely (or certainly?) enough, I never see people opting for this route.