The comment in question specifically referred to D&D, but I think we can broaden it to all fantasy RPGs in general.
I personally love it when players take the time somewhere in the first session or two to provide me with some kind of background on their character. I realize some games have a basic background generator built into them. (Notably 5E and W.O.I.N.)
Dungeon Crawl Classics has its infamous 0-Level funnel wherein the PCs are considered peasants who decided to take up the life of adventuring and miraculously survived long enough reach an actual character class. Unfortunately, the town is now missing its butcher, candlestick maker, haberdasher, and about a dozen other peasants who went down into some scary hole in the ground and never returned. Some background of the surviving actual characters is already built in. That poor, poor village, though.
Whether it provides a statistical advantage or free item, it should still be worth creating a background.
Every character in books, theatre, TV, or movies has to start somewhere. True, Peasant #3 in the background of the bar scene probably lives out his entire life in those ten minutes, but he still might have had a cool backstory. If the group actually took a minute out to talk to him, they might even learn something. Maybe not even relevant to the plot, but… can’t win em all.
I know a lot of games are trying to coax players into coming up with more elaborate backgrounds with all kinds of rewards. Everything from skill boosts to items, even magic items can be awarded depending on the system and whether or not the GM thinks the player did enough. I’m even somewhat guilty of this. I’ve handed out Experience points for anything over half a page but fewer than three pages. I’ve also given out minor trinkets or even masterwork/low end magic items for a well-written, well thought out background. I like to have something to work with as much as any GM does.

Plenty of resources to help players generate that background.

My all time favorite books for generating character backgrounds are Central Casting: Heroes of Legend. (Also Heroes Now! and Heroes for Tomorrow.) A quick search of DriveThruRPG gave thousands of options for fantasy character backgrounds. A quick Google search of fantasy character backstory generator listed several hundred more options, many of which were free.
Even the often maligned 1st Edition AD&D Unearthed Arcana had something of a background generator vaguely sandwiched into it. 3E D&D had the Hero Builder’s Guidebook which contained a very nice background generator. One of my absolute favorite 4th Ed D&D books, the Player’s Strategy Guide also had some great tools for building a backstory. These are all very helpful if you can find them.
Players: Please don’t write a novel about the character?
Lovingly submitted, your GM. Seriously, too much background story is a lot of reading, however interesting, for GMs who usually have a lot on their plate already. Personally, I find anything much beyond three standard typed pages to be overkill. Other GMs might see this differently.
It’s good to give the character some depth of personality. Reason and motivations that have helped shape the way the character acts in certain situations are good for roleplay. Not every character has to be suitable for television or movie drama. Too much background might make it look as if the character should already be 5th level and have some really decent magic items.
On the other side of this, I always ask players for at least a half page (even hand written) of background for their characters. I know there are plenty of minimalists and adult players with other commitments. I understand having a busy schedule. But, half a page? C’mon. Three key lines. I’m not picky.

Here’s an example:
Bronk, Half Orc Fighter:
Bronk was born to a family of peasant sharecroppers who were very poor. Father was an Orc cast out of his traditional Orc clan and went to live with mom’s Human village. Bronk heard many tales from adventurers at the pub and thought adventuring would bring him more gold than farming and help his family.
Count it! Now we know a little about the character, who/what is important to him, and why he started adventuring. Not overly dramatic. No distinct character advantages written in. Manageable in less than 5 minutes.
Score! 500 XP for the character and inherits dad’s old leather armor and gets to keep his trusty farm ax to help him on his was courtesy of a grateful GM. Nothing freaky. No angst for anyone. Easy.
One of the new, great ongoing Internet debates.
Thank all of the gods, not another D&D edition war. (Although it’s probably coming.) One of the new Twit-ragers is going to be Backstories: Are they necessary? I know I’ve already seen some shameful examples of this, not to name any names.
There are two main camps of (mostly) D&D players on this one. Either you’re big on the newer editions and think backgrounds are an absolute must-have OR you’re totally old school and think backstory is something that might happen later if you absolutely must.
I’ve done it both ways over the years and seen it used, mistreated, and even abused in the past. Modern-ish D&D is systemically built about more drama and depth of character. Looking back and 2E and older, we were happy if the character survived long enough to warrant putting a last name on the their line.
Heck, I remember a time when physical description was asking a lot. Wouldn’t matter much if the character fell 30′ into a dungeon’s giant meat grinder. Alas, poor Dave Number 3 we knew him for one hour. Oh, look it’s Dave Number 4 coming around the corner with fresh rations and torches. Yay!
Now we have all kinds of Death Saves, healing and other second through fourth chances short of bribing the DM. (I accept bribes, or more like Faustian bargains, but at least your character gets to live.) 5th Ed has built up the notion that story comes before statistics. Do kids even have characters wander into dungeons any more in D&D?
Hopefully this has provided a little amusement. More on the story of backstories to come someday. Thanks for stopping by. Please be good to one another.