HP has a long history of very sophisticated electronic test equipment. A great deal of innovation and hard work went into development of that equipment, including many things that hadn't been done before. Many other tech companies used HP (and Tektronix) gear when developing their products. Aside from the many tech contributions, their corporate culture was certainly one to admire. HP was better known to engineers than consumers, but they did do some things that crossed over. The HP-35 hand-held scientific calculator was the first product of it's type I ever saw (and owned too...), certainly seeming worth the $400 one cost back in the day (around 1972). HP was constantly pushing the state of the art. HP wasn't merely successful, they were special.
I was sorry that the HP/Compaq computing combination got the HP name. I wish that had stayed with the real tech products, but in Agilent tech lives on. HP certainly stands out from an era when the U.S. really shined as an engineering and manufacturing leader. HP wasn't another Dell or Gateway.
There are (and were) tech companies with a past that goes way back. For instance most think of Motorola as a cell phone company. They were huge in semiconductors (some of that lives on in Freescale), but how many remember them as being the ones behind the first car radio or first under $200 television set, or making communications gear that went to the moon?
In comparison, I find it a little sad to see highly valued companies like Facebook that don't really seem to produce anything. If it had never come into being, would we have really missed much that mattered?
Unfortunately, being a mature company with unsexy product lines like scientific instruments wasn't popular with investors in the late '90s and the bean counters and MBA types were given free reign to strip and gut HP so that now it's little more than a marketing division for cheap, Chinese-made crap with funky bezels.
Everything good about Silicon Valley is owed to that company, and to its founders. It's impossible to place Fiorina's actions in any sort of context until one understands that.