Are there a number of slightly different and incomplete variants of LINQ, like there are SQL DSLs in Scala? Because if not, then LINQ is "the right way" of doing this kind of thing. And if I remember correctly, LINQ is also useful outside of the DB domain, for things like filtering arrays and so forth.
I once read an article about how Java programmers can hold a conversation on the topic of upsides and downsides of multiple dependency injection containers while C# programmers only have one available and have nothing to say on this topic. That article concluded that having one "good enough" solution can often be better than having multiple slightly different and incomplete ones, even if each has its own strenghts, and I'd say the same is true when it comes to the C# LINQ vs. Scala SQL DSLs.
The Scala equivalent is called Slick, and it's the only SQL DSL that approaching anything near widespread use. I fail to see how incomplete projects on GitHub which happen to be written in Scala are relevent to this discussion.