> I initially saw oh ok, there are a ton of people making these apps, it must be profitable.

If you look at a dense market and decide to join in because you see potential profit because the market is dense, you're already destined for failure. Everyone else already has a head start, which means you need some sort of differentiating feature to be competitive.

Why would I pay for blog software that's half baked or doesn't offer anything new? Or a to-do list? Or time tracker? Or invoicing tool?

The author dances around this, but it honestly sounds like the product they built wasn't remarkably good or novel, and was positioned against incumbents that were plentiful and often had existing success. The failure here seems to be a lack of business plan beyond "join the pack and make money".