SpaceX took anybody who was paying attention on a roller coaster today with back-to-back countdowns to less than T minus 60 seconds before aborting. Way more nerve-racking than any Thanksgiving football game.
Your initial reaction to the aborted launches might be 'SpaceX clearly screwed up and got their just desserts for building up hype.' But I see it in a more positive light. SpaceX was working as close to the principles of 'try fast, fail fast,' as you can when you have a multi-million dollar rocket and payload on the line.
Negative reactions to glitches like tonights launch and last month's problem in the Dreamchaser's landing gear contribute to the glacial pace of big engineering innovations. It makes sense when you consider that going very slowly on a project to try to cover all your bases only raises brief, vague annoyance. Actually trying something big and not succeeding perfectly draws at best harsh criticism. So my take is that if nobody innocent is hurt (physically or monetarily) actually going for it should be applauded.
SpaceX could have spend many more months figuring out potential failure modes, which *may* have caught this particular one, but there is always something else that could go wrong. Instead, they built a system that could safely shut down at literally the last second in case of a problem. They also could have gone down another route and said 'ehhh, it's probably fine' and ended up with a true failure, rather than just a postponed launch.
And on a semi-off topic note: I'd like to point out that SpaceX is NOT a startup. It was founded more than ten years ago and has thousands of employees. Yes, it's privately owned. Yes, it breaks the aerospace industry mold by following a Silicon Valley model. But please, if someone starts talking about space startups, please don't respond with 'oh! Like SpaceX?'