So, the short answer to this question is yes. All lagers are not bad beer.
I am not sure where this thinking started although it's easy to speculate. When craft beer started making inroads, the beer market was awash with just one style of beer, pale lager. This bastard child of Pilsner, came in three basic categories, cheap, mid-range and premium. It was often brewed with corn or rice to cut the body and flavor of the beer. Whether this was in response to the demands of the market or evil, cost-cutting tactics performed by profit obsessed brewing corporations, the result was the same. The beer industry had become a race to the bottom as big brewers competed to brewed the most subtle, lightly balanced beer possible. Remember one brewery with an ad campaign that promised their beer would do away with bitter beer face?
When the original craft brewers starting producing their beer, they were often working with the smallest of budgets and pressure to turn out beer as quickly as possible to pay the bills. Ale turns around much faster than lager and is generally easier to brew right. So, the first beers brewed by these beer pioneers tended to be ales, thus drawing the line between pale lager and ale.
The answer may also lie in the comparison between lager and ale. Speaking in the broadest terms, ale has more flavor, aroma and character than lager. When the original sin of the beer industry was that it was based on a style designed to have the lowest possible levels of all three of these characteristics, it's easy to see how the whole situation gave lager a bad name.
However it happened, it's wrong to paint all lager with the bad beer brush. There are many tasty styles of lager out there that are definitely worth exploring.