Do you actually work in these environments, or are you making assumptions?
Resource contention is a problem in pure software companies, too. I used to work for a small pure software company in rapid growth. What did we have? Legacy code nightmares that were as bad as or worse than anything I've seen in the Fortune 500 (like building the core product on antique Borland C++ where there were only 9 licenses in the company and new licenses were no longer for sale and hadn't been for years, while the UI was written in Java Swing with a table kit from an out-of-business vendor). And almost all growth money went to expanding sales staff... engineering got screwed. They sold (and sell) terrible quality software, and they make a fortune at it.
Meanwhile, I'm at a massive health care company, and they hired me because they're committed to radical improvement in how the already-okay software is built and deployed. We're working hard on a serious continuous integration pipeline, and I expect us to be as good as anyone in a year - our reference points for "Why can't we do this?" are companies like Netflix. We're after that level of smoothness in the process, and we'll get there, or at least get close.
Don't let conventional wisdom tell you who is and isn't good at software.
edit: I'm reminded of going to a meetup about selling to the enterprise in Silicon Valley some years ago, and the twenty-something Stanford crowd were convinced that because these big companies have big failures, that they must suck. I pointed out that if you worked at a startup with $50M revenue, they'd be pretty successful, right? I've worked on several projects with annual development budgets larger than that. It's expensive and risky because they're operating at scales that most of the HN crowd can't even comprehend.