I'm not saying that you wouldn't choose a good open source alternative if it exists. I'm saying that you shouldn't run off and implement something that exists commercially if your only reason is that the commercial thing costs money.
1. Our problem set is not novel, we're more or less like many others out there and collectively we are a market that a vendor can build a product for
2. Since we have significantly more revenue than a startup like AirBNB we can rationalize and amortize an ongoing expense
3. We actively try not to do things that aren't our core competency
4. Even if we wanted to we have plenty of human resources but not the talent to build our own analytic DB or data visualization tools
I think AirBNB is likely a much different company than most. Their approach to talent attraction/retention, novelty of problem set, ability and tolerance to make a multimillion dollar capital investment in analytic database and visualization tools, etc, etc. In their case the upstart cost of building a custom thing and the value prop likely makes sense.
We also use some of the previously mentioned visualization technologies and get generally poor results by all measures.
If AirBNB has a few engineers around who are part of solving a unique challenge AirBNB has, then they are probably getting a better deal than we are. I'd wager their productivity per resource is significantly better, not to mention licensing, infrastructure and control over product features. That said, not everyone is AirBNB and has the ability to attract and retain that type of talent.