Yeah, that was my assumption as well...that they just want to be at the front of the queue...
Not necessarily at all.
As you watch the B/A spread and quantity-offered(s), you'll see behavior that I liken to Halloween kids lined up on a stoop: little kids might all rush forward, sacks opened, yelling "Trick-or-treattttttt!" and gleefully accepting whatever sugars are handed out. The bigger kids though -- they hang back a bit, mindful of a certain capacity limit in their candy sack, mindful that sugar is just *dang* heavy to carry around, mindful that those puffy little treats like 'flavored' dots and Sweet-Tarts and such just do *not* do the joy so much..... These bigger kids are waiting for the houses that are handing out Snickers and Hershey bars and Chunkies (are CHunkies even made anymore??). Keep watching the quantity(s), and you'll see a 'block-of-size' before-which can sometimes hop smaller offers... but the big boys (and girls?!?) have a definite idea of where they wish to trade, and move with the underlying, and not so much with the option/strikes.
(BTW, 'economically' this is an auction, and the observations you're making right now apply equally well to markets in art, tomatoes, tax/property(s), wholesale cars, etc etc etc. As much as possible, the big boys will let the little fishies scramble for the tidbits (and exhaust themselves), knowing that "Of Size" needs to be around for the long run. Hell, just watch a closing eBay auction! [With a beer in hand, thinking "Don'tcha just love this stuff?!?"])
Thanks!