I see similar arguments when folks say we should boycott a certain brand of gasoline.  A popular urban myth is that if we boycott a company like Exxon, we can really hurt them.  Not true.  All you're doing is hurting the retailer or convenience store - because they already paid for thousands of gallons of fuel.  Gasoline is fungible and there is no such thing as "Exxon" gasoline versus another brand.  Exxon continues laughing all the way to the bank!

It's a similar story with beef.  Buyers purchase half-cows that have been processed, and there is little brand allegiance unless you're in the organic or grass fed specialty markets - a side of beef is a side of beef that can be graded Choice through Prime.  It too is fungible, and the retailer buys sides of beef and pays cash before selling it.  The grower, feedlot, slaughter house, and truckers have already made their money. 

Digging further, if demand does in fact fall, which can at times, the market corrects itself by lowering the price of beef ... which in turn can cause consumers to buy more of it!  But there actually is a shortage of good beef now, and meat prices have shot through the roof.  The economics is quite puzzling and what seems like a simple solution just doesn't work. 

Which is why I say in answer to the question - do what you want to do, and if beef isn't on your personal menu, avoid the stuff like the plague. 

Food animals typically do not suffer a "cruel factory farm existence" when raised in modern livestock confinement operations. Such animals are well fed and watered, protected from extreme weather conditions and provided with veterinary care when needed.  They also aren't subjected to traumatic death by predatory animals.

In the case of pigs, modern harvest plants use stunning methods, including carbon dioxide stunning, to put the animal into deep unconsiousness before they are killed.

Producing pork and poultry in modern confinement units actually has less impact on the natural environment than open lot raised animals. In a confinement unit, feed efficiency (pound of feed it takes to make a pound of meat) is considerably higher than that of open lot animals, thus fewer resources are used to feed the animal to market weight.  In addition, manure is contained until the opportune time for the farmer to apply it to fertilize crops.  Conversely, manure from animals on open lots typically washes down gradient with each rain and ends up where gravity dictates, rather than where it will do the most good.

Although you need to be an informed and smart consumer, your conscience need not be burdened when you buy meat at the grocery store.  In general, the animals are well treated and the United States has plenty of grain to feed animals with the goal of producing nutrient dense food for hungry people.

Can you imagine standing on concrete all day rather than the ground and grass your feet are designed no stand on? That's the life of feedlot cattle.

I don't doubt that you were around when the move to confinement systems accelerated.  But how much time did you spend on a farm?  Cattle, hogs and poultry are all gregarious animals.  They don't spread out a whole lot.  In fact, during the winter, you have to watch out for hogs piling up in shelters and crushing each other in pastured pork and open lot systems.

Dairy cattle on concrete? Yes, in the Midwest, East, and Southeast where there is a lot of rain. And the concrete is kept pretty clean by scraping or flushing.  And the cows are usually bedded down in free stalls that are clean.   In the West, a lot fewer dairy cattle are on concrete because of the drier climate.

As far as wading feces, based on my experience growing up on a 35 cow dairy farm I can tell that dairy most cattle in pasture based systems spend 3 to 4 months a year wading mud\manure.  Many small dairy farms moved to confinement systems for a large part of the year due to mud problems.

Beef cattle on concrete? Not very much.  Most are fed in dirt lots.