Can we please have a correct outpoint instead of one frame offset?
Kevin Monahan commented
Rajko, all NLEs behave this way because of the nature of video "frames" having a "leading edge" (beginning of the frame) and a "tail" (the end of the frame) and the UI which displays the current frame at the beginning of the frame.
In one other NLE, there is an option to press Alt/Option when using the Playhead to mark out at the end of the frame, which is what you want. I think that's probably the best possible compromise. Would that be OK? The other possibility would be a preference of some sort.
When marking both In and Out, I suggest you check out the Mark Clip function, which marks out as you'd expect.