37Signals' products weren't profitable for a year or more, if memory serves. They took "investment" from the other side of their business (consulting). Every month, when their product revenue grew, I'm sure they were thinking, "Wow, we're going to be profitable in X months"... and eventually, they were.
Product profitability takes resources. You need:
1) Time (you can accelerate this with cash if you're disciplined) 2) Money (you can use savings, investment, or you can "buy" money/time with consulting)
That's immutable.
EverNote and their ilk ("our ilk", I should say, as RescueTime falls squarely in that world) is trying to build a business formula that works... And it looks like they're succeeding. Presumably they could cut dev staff, stop all experiments, and get to profitability MUCH sooner-- maybe even today.
But that's how business works, right? It's all about intelligent debt to ultimately maximize the metrics you care about (presumably some combo of growth, revenue, profit, and lifestyle). You hire an employee, and you are spending time and money on them for a while before they are really contributing. You take funding so that you can run the experiments that require capital. You take your consulting profits and pump them (and your spare time) into product efforts. And some businesses scale differently than others (Amazon is a great example).
That's ALL DEBT. And it can all be smart debt (like a mortgage used to be!).
Just because companies are choosing a different flavor of debt or choosing markets that scale differently doesn't make them bad. I personally am THRILLED to give up a relatively small stake in our company so I don't have to consult and can run experiments about as fast as I want to.
Scarcity FORCES you to be smart-- but the lack of scarcity doesn't mean that you CAN'T be.