open source doesn't necessarily mean you're giving it away for free. often the product is actually a service and having the source isn't necessarily useful to consume said service.
Sure but in this particular case the product is absolutely being given away for free. There is no service attached to having a faster linker, you just grab the code and off you go.
The only monetization it has is basically a big sign saying "please pay something if you want to", and not enough people want to.
If people can't grab the source and use it to run the service, where is the incentive to improve the source? So this may be "open source in name only" - it has an open license, but it doesn't actually build an open ecosystem around it.
The only monetization it has is basically a big sign saying "please pay something if you want to", and not enough people want to.