It's the main interface to entity framework, which is an abomination.

Also, while there are some performance gains to be made from things like delayed execution, I think the loss of predictable behavior negates any performance gains.

Also, all of the syntax surrounding Linq... lambda expressions, anonymous functions... it's just a cumbersome and hard to understand syntax. At least they made it so you could step into anonymous functions with the debugger.

Basically Linq allows you to replace 3 or 4 clear and obvious lines of code with 1 harder to understand line of code with probably zero performance gain. But at least you can claim on your resume that you used Linq.

There's a trend in software development to be cool or clever. And this is always at the expense of clear and understandable. "Oh, you're not using blabla? I'M using blabla." as the developer looks down their nose at you for not being bleeding edge enough.

If you can't tell, I usually take the role of a senior developer, with maybe 3 to 6 junior developers working for me. And I'd much rather have programmers writing clear, understandable, and easy to maintain C# .net 2.0 framework code that just fricken works. And if one of those developers leaves the project, I know that I can easily replace that guy, and the new guy won't have any trouble figuring out what the code does.

If we're going to be professional adults about the job we do, then we have to ignore what's cool and trendy and focus on what's good for the business. Sometimes you really do need the hard techniques. But usually, there's a replacement for EF and Linq that performs better and is easier to write and maintain.