People still do this even without flash. Lots of people post tiny online games that require dragging the mouse with the left mouse button pressed and it's clear they forgot/ignored that the majority of people are on laptops
That's true, though for me the different isn't as great as with pure touchscreens, and I always was willing to accept that as a downside of using a laptop rather than blaming the game itself. I guess nowadays that would be a harder psychological position to maintain with the ascendency of laptops.
The cruellest thing for macbook users are games that require clicking both mouse-buttons simultaneously :P