On the flip side, without investors taking risks on new neighborhoods, many of them might not have developed into frum areas
My experience has been the opposite. I was the first one to buy in the area. After brokers heard that there is a frum family in the area, it was used as a marketing tool to let investors know that this is a good area to invest in. What resulted is having families that would have moved in out bid by people who then placed "undocumented citizens" in the houses. So no, the investors slowed the growth of the neighborhood.
I
f you’re getting outbid by an investor, you were bidding to low in the first place.
Nope. Investors that have cash can dump it on a house outbidding those who don't have such cash on hand. A cash offer may outbid a higher mortgage contingent offer.
they aren’t required to do so by any halacha.
Hence the novel brshus hatorah component.
it’s none of our business anyways.
When they are stunting the growth of my neighborhood, it's very much my business.