Philosophy is great stuff, I've read my share. I've also got a few linear foot of questionable material on my bookshelf. The Carlos Castenada stuff is clearly bullshit and mostly there just as a cautionary tale. I can't make up my mind about Heidegger because I just don't understand his writing . . . he's either brilliant, or he's blowing smoke up the world's fundament; heck, maybe both.

One of my cow-orkers took a bunch of philosophy in college (I think he was at Stanford, in the mid 1970s). He said his course on logic spent a lot of time on DeMorgan's theorem. I don't know about other s/w engineers, but this is something that I use practically every day, usually without even thinking about it -- I don't even remember being taught it, I just sort of figured it out one day early in my career, while I was cleaning up some badly written conditionals.

Cuban's point about knowing philosophy (... which branch? who knows?) is still useful. But it's equally useful to have a wide background in other things than software, when you're writing software. I had a manager once who had a law degree and a Jesuit education, and he was formidable when it came to dealing with department politics and HR bullshit. Just about any value of X in the phrase, "I can write software and do X..." will do you well.