Kind of yes and kind of no. They're not bad beers because we see them as mainstream but they're definitely bad beers because of their mainstream business practice; mass produced cheap beer. They're produced using the cheapest processes possible for the sake of selling people a large quantity for less. Obviously a beer being good or bad is up to opinion, but these are as close to water as you're going to get in terms of beer. The flavors we associated with a beer of good quality are completely absent; malty, hoppy, spicy, citrusy, or any variation you like. It's literally just water with just enough alcohol and yellow coloring to be called a beer. Is Guinness better? I would argue a good pint of Guinness is much better than your typical mass produced cheap beers. It's also easier than ever, unfortunately, to get shitty Guinness because it has become so mass produced. You may get a hearty Guinness or you may get watery brown from the end of a keg that leaves you wondering if Guinness was ever any good or that its competitors are just so bad.

Cheap beer has a purpose; it's affordable for the masses and has a little bit of alcohol. We all drink it all the time because of that... it's the same concept of stopping by Pizza Hut or Dominoes for a small pizza. They're the shittiest and cheapest in comparison to some fancy artisan pizza maker, but it's convenient and the opportunity cost makes it worth it. Hell, many people love those types of pizzas... but then you get people like me who float from pizza place to pizza place knowing the non-chain places may have a better and higher quality method of making something because they want it to be higher quality at the cost of volume.

So, you know, cheap beer is like cheap pizza. We're all going to buy it, most of us like it, but when it came down to a taste test we'd be lying if we didn't know there is much, much better out there for a little more effort and price.