Not entirely. I mean the characters dont say it like your examples, but similar things have happened.
Fighter: "Dude, the pet anaconda might stand out a bit you think?"
Barbarian: "Yeah, let me think what we can do. Wiz, can you shrink animals?"
OR
"Okay Dirinian, you set fire to the left flank and the front rows, while our hired cavalry sweeps in from the back. Castamir, make sure there is an opening in the rear for the camp followers and children to escape."
And fair enough. But, again, at the end of the day, what changed? The animal companion is still hidden and fades into the background (not the mechanical version, just, not in the front of play) and those orc children escaped. And, after the third, fourth, tenth time, most groups are just going to take it as read anyway.
This is the point I keep coming back to. We already Background tons of stuff in play because it's not terribly interesting. How many groups actually, consistently, track spell components? How many groups worry about paying the monthly living expenses? So on and so forth. Sure, you might do it from time to time, but, realistically, it just fades back and becomes a non-issue. Do you seriously destroy a wizard's spell book every time he falls in water? Or gets fireballed or whatnot? Naw, you just take it as read and move on because it's too much of a PITA.
Here, we have examples that only really affect one player and the DM. The rest of the group couldn't likely give a toss about it. Do you seriously care how we hide the Druid's animal companion every single time?
The funny thing about this conversation is that some posters, like [MENTION=3400]billd91[/MENTION] and [MENTION=6919838]5ekyu[/MENTION] are framing it as a powergaming thing. But, look at that warlock's patron. There's two sides to that. Sure, if you have an active patron, then the patron might ask the PC to do something. But, it also works the other way. There's times when the PC can and should be able to call upon his or her patron for help - be it information, or contacting other NPC's or whatnot.
By backgrounding, the player loses that side of things as well. Sure, the DM can't force behavior from the player, but, by the same token, the player cannot expect to get anything as well.