Ask HN: Is it worth pursuing an idea ...

This question doesn't make sense. "Big Companies" have thousands of developers. Thousands. You're 1 guy, maybe a small team of 5. "Big Companies" could easily implement ANYTHING. But guess what? There are thousands of YOU out there. More than at any big company, and they can't do EVERYTHING. So just do it and stop worrying about it.

Ooh, I really like this logic. (:

If they haven't done it yet, then yes. Then politely allow them to acquire you for something in the low 8 figure range.

Microsoft could have built Facebook. But they didn't.

Upvote x 100. This is the mentality all developers and entrepreneurs should have when pursuing a serious project. Unfortunately, we don't hear wisdom like this enough.

There are many ideas that a large company could implement on a whim.

However it is often the case that due to internal politics and bureaucracy a company might have many reasons not too - or be slow to adopt - or have to hobble with perceived business goals.