1) It updates the setting slightly to 5e, tiding people over until more content could be released.
2) It serves as an introduction to the Realms for people playing the storyline adventures or in the Adventurer's League.
3) It works as a player's guide to the Realms for gamers playing in that setting in himegames.
4) It provides a small amount of crunch to satisfy that craving.
5) It served as a cross-promotional product with Neverwinter and Sword Coast Legends.
Just stop it Jester, it's getting ridiculous. Are you selling WotC's merchandize for them, or what?
Let's comb through your own post and see what it says, okay?
"tiding people over" is your opinion but you don't present it as such. Lots of people aren't, but you choose to ignore this.
Why would you even write "until more content could be released". The 3E FRCS was published in 2001, just one year after the edition it serves was published. It is 320 pages long, with a font size smaller than SCAG. It won the Origins Award for Best Role-Playing Game Supplement for that year.
By any reasonable standard of comparison, we are right in being disappointed. Why do you let WotC off the hook in this case as in so many others? Why not support the very valid criticism that in roughly the same time frame, WotC has managed only to publish something "to tide us over", instead of publishing perhaps the richest and deepest campaign guide ever published, something that truly is tiding myself over even now, 14 years later?
You could have said "SCAG is a pale shadow of the FRCS'es of yesterday", yet you don't. And never do.
Moving on...
2) nothing to add here; you're right, it's an introduction. But only an introduction.
3) it does not do anything of the sort. SCAG is definitely not working as a stand-alone product - it is definitely leeching off the efforts of past editions. Introduction yes; complete campaign guide no. And as a player's guide, assuming you mean "stuff for players", meaning "crunch", it is very light. Yet none of this can be learnt from your post.
4) "It provides a small amount of crunch to satisfy that craving." Wow. You even turn the small amount into a positive. And you speak for all of us when you feel satisfied by that small amount.
You know Jester, if people still take you seriously after spewing that sales pitch...
SCAG isn't completely void of useful info. But this is a thread where the OP is asking if he has somehow missed something or if it really is that light.
A much shorter reply from you could simply have been "yes, it's much lighter than for previous editions, but I bought it anyway and recommend you do too, because it's all we're likely to get in quite some time."
Just sayin'