It’s dual use, like Metasploit. It’s hard to predict whether black hats or white hats will use it more often or not. I think your conclusion is more intuitive, but let me play devil’s advocate.

LotL is too advanced for script kiddies to pull off. You’re already dealing with an adversary with some sophistication, who likely have the time, skill, and resources to create their own LOLbins (or buy them on darknet forums). Infosec is an asymmetric conflict: the adversary has a much easier job IMO. It’s always easier to break something than to build it.

Blue/purple teams have little incentive to build their own LOLbins. There is another asymmetry here: blue teams are developing these to target only their networks. Red teams are developing them to target every network. Open source is the way to resolve that asymmetry.

With these becoming public, blue teams can simulate a LotL attack, develop indicators of attack, and write rules to trigger alerts.

In general, adversaries prefer their tricks to remain trade secrets. Once they’re known, documented, and commodified, they become far less useful.