Is it bad practice to write inline event handlers ?
For me, I prefer use it when I want to use a local variable in the event handler like the following:
I prefer
You put the two samples together. It is clear that the second option (which you don't prefer) is the most readable.
Code readability and maintainability are very important. Keep things simple, as easy as possible to understand. Lambda expressions are generally considered harder to understand by majority of people. Even if they are a second nature for you for others might not.