[Raj_Copi_Jin]

Now this all encompassing definition of entertainment is problematic for me.

Oh yes, I too find it problematic in other circumstances. I can't call most of my favourite films as merely entertaining. There's invariably so much more to those films. But in this discussion, there's a bigger problem. The sense in which "entertaining" is used in this kind of discussion is just too close to saying, "to hell with others, I like it this way!" Which is exactly how the so-called serious film watchers think of the films they like. That's why, I think, it's important to make this point (even if it oversimplifes some things). And as you say, the distinction is amorphous (very much so, I'd argue) and the word has very different connotations for different people (at different times). For instance, I think I'd not find it disagreeable if someone says Hey! Ram is not "an entertaining film," but would likely disagree if the same is said of, say, kuruthippunal (of course I'm intentionally picking a film just as serious as the former).

Eitherway we know at some level - not saying this is easy to articulate, and that is what we shall attempt to here - the distinction exists.

Incidentally, this is exactly what I wanted to say in response to your post in the other thread. We cannot escape by fudging on the defintion of the genre! Much as we like 'அயன்' and think it's massy and entertaining, it's obvious that it's not like 'கில்லி' or 'தூள்' in some ways. I certainly do think 'அயன்' is a proper masala film, but it differs from the above films in certain ways and I suppose we must be acutely aware of it.
Of course, you also say, "தனியொருவனுக்கு படம் சிக்கவில்லையெனில் genreஐ ஒழித்திடுவோம்." But I'm trying to see if there's some middle ground.