I have a policy about not criticizing people in their house, and this is definitely not my house.
That said, there are some markets large enough to sustain many companies. Bingo cards probably won't support a company on the trajectory that YC would like. A/B testing, though, already supports many companies, from several big-freaking-consultingware companies down to VWO. There is room for more, and I'd suggest people remember that the biggest competitor isn't a just-launched startup or even Google. It is "Customer decides not to A/B test." This competitor is very popular, and has 99% share in the A/B testing space. Heck, it probably has 90% share among HN readers!
There's a difference between being critical and being disrespectful or rude.
And the size of the market is irrelevant. To run with your analogy, the question is whether it is ethical to invite someone into your home to join a support group for small entrepreneurs and then fund a much larger team to chase their ideas once you learn about them. For an organization that aims to support entrepreneurs, this just looks bad. There is nothing wrong with competition, but they should have passed the proposal to someone else to fund.
Similar argument could be made about the 99% of people who don't play Bingo - yet :) I agree with you otherwise that the two markets are of different potential sizes..
That said, there are some markets large enough to sustain many companies. Bingo cards probably won't support a company on the trajectory that YC would like. A/B testing, though, already supports many companies, from several big-freaking-consultingware companies down to VWO. There is room for more, and I'd suggest people remember that the biggest competitor isn't a just-launched startup or even Google. It is "Customer decides not to A/B test." This competitor is very popular, and has 99% share in the A/B testing space. Heck, it probably has 90% share among HN readers!
That is the enemy. Focus on killing that.