Frankly, when compared to Intel, Reddit surely looks like something that
  was just "cobbled together". 

Like any other large company, Intel regularly buys some of these, so called 'cobbled together' startups. Those startups have business plans of their own and technology of their own, but no interest in taking on Intel, Motorola or any of the other giants. That's a valid business proposition and not a sign of weakness.

  They don't have to deal with quantum effects, current leakage, and that
  kind of stuff.

You're either romanticizing hardware or you're underestimating software. I'm an experimental physicist: I fully empathize with your respect for the engineering problems a company like Intel deals with. However: software startups mostly aren't solving engineering problems. That's not their goal. It's like criticizing the Los Angeles Lakers for not winning the Super Bowl.

are often not it's just too easy to disregard the problems each distinct piece of software faces.