I found it interesting skimming through the pages of this thread. Here's my view on the matter, but without all the "well you're not a TRUE F1 fan" bollocks that was constantly spouted (mainly by tex).
While I am a fan of the McLaren team, I have a great affection for other teams as well, especially Williams, Lotus (Caterham), Red Bull, Sauber... infact, the majority. If McLaren were to leave, for any reason at all, I would be greatly disappointed, but I would by no means cease to watch the sport. I would carry on loving F1 all the same.
The seasons that I value most in F1, are those that are close between two or three teams, and which provide situations in races that keep us forever guessing. If I had the choice to have a season where McLaren easily dominated everything OR a season which was contested very closely at the front, I would chose the latter. This would be with the hope that McLaren were able to contest for the win, and hopefully win it at the end, of course.

People who state that they would never watch F1 again if their favourite team or driver were to leave, then I suggest they should just look into treasuring the memories of what's past and look forward to an exciting new future. A change is always as good as a rest.
What's great about supporting a team, is that you can have someone to cheer on at home and at the race. I love wearing the team kit and waving the team flag at Silverstone, and being amongst many other like-minded people to create a chorus of passion, noise, adoration and support. As long as McLaren are around, I will support them, but the fact that I possess an strong love for the sport as well as just the team, means my focus is always spread out further than just the Woking squad.