You don't even have to use LINQ at all with C#, it's an extension library and not one that needs to be referenced or is even included as a default namespace. LINQ is very convenient to use on in memory objects where there's no noticable performance hits. Even LINQ->SQL produces somewhat optimized SQL. How else would you bend data into shape without an ORM layer? Writing custom stored procedures, adding a whole bunch of new service methods, or manipulating data tables directly?

This 'cancer' is simply a data layer; if you use proper design patterns and seperate your layers correctly, you can surgically remove this tumour and replace it with another ORM.