> How was the Alpha a bad bet?

Not technically (Alpha ISA had its good and bad sides, but was decent enough), but economically. DEC just didn't have the marketshare and thus economic muscle to survive in a game of ever increasing R&D costs for each successive generation. Hence DEC ending up acquired by Compaq, which then was acquired by HP.

HP also saw the writing on the wall, and developed Itanium with Intel as a replacement for their PA-RISC, thinking that Itanium could benefit from Intel's huge economy of scale in chip manufacturing. And after acquiring Compaq (with DEC Alpha) it sunset the Alpha as well in favor of Itanium, for the same reasons. Well, we all know how the Itanium story turned out.