I notice that when a lot of people call me in FT8 mode, they skip the first line with their callsign and grid square information and just call with their callsign and my report.
I make a point of not responding to those callers.
In my view, the first line is there for a reason and so it should be included in any QSO.
Also, I happen to collect grid squares and when the calling station does not give that information, I find it a real nuisance to look them up, in mid QSO, on qrz.com, so that I can include their grid square information in the logging field when it pops up.
Thirdly, I believe it is part of the "etiquette" of the mode and it should always be included.
I know that a very large proportion of operators disagree with me but that's just the way I feel.
If you see my sound card calling and you want to work it, then please include your grid square and allow the QSO to go through the proper sequence.  It's pretty simple.
73 and thanks, Alek. VK6APK