Worst beer I ever tasted was Colt 45 in the U.S. Around 1980. It tasted like it had sat in the sun for a week in a clear bottle. If I remember correctly it cost about 25 cents a quart. And that was a ripoff. Next worst was Coors. Tasted like watered down rice. Foul. The only decent beer was a Miller's Old Style we tried in Chicago.
You have revealed the trade secret of Colt 45. You must not have had Steele Reserve, an even worse malt liquor, but what the hey, after two forties of 7% brew, who cares?
There were very good US beers before craft breweries came along. Ballantine did an outstanding IPA. Prior made a malty lager and a schwarzbier following directions by a Czech brewer who fled before the Nazis. Good all-malt lagers in German styles include Berghoff (got its name before Hitler's hangout), Augsburger and Christian Moerlein.
But all except Berghoff were either gone or on the way out by 1980. You hit the scene at a low point. The trend prompted the craft brewing movement. Real ale in the UK had a like stimulus but developed in a different direction.