@ Luminis
When you play Forza, a *lot* of information about what you are doing is uploaded. Are you circuit racing? Are you drifting? Are you in the "playground" type games? Are you painting, in the SF or AH, etc, etc, etc. This also includes race-lengths from user-created multi-player races.
Turn 10 analyzes all of that data to determine which features are being used the most, the least, and in-between. That information factors into future development decisions.
A few anecdotal comments:
There are a couple of established racing leagues, where they run races of lengths that pit-strategies would actually be beneficial. But how many people are participating in that? A few thousand, maybe (and I think that's being generous)? TORA has just under 1,000 players listed on their assigned-numbers list (no idea how many of those are actively racing). For reference - there are over 4.1 million times posted to the S-Class Alps Festival Leaderboard (the first race you run when you start the game).
When you look at the user-created races list, how often do you see lobbies set up for 45+ minute long races? Ever?
Back with FM3 and FM2, it was not unusual to see posts here complaining about the Endurance races. They were too long and boring. Many people talked about how they used the "hired driver" to knock those out (to get the 100% achievement).
Way back in FM2, you could pull up players' multi-player stats - it would show number of races, total time spent in those races, number of wins, etc. Shortly before FM3 was released, I went through the Leaderboards and started writing down some stats. I picked players at random (from the Top-500 on each LB), and recorded the number of races and total times. I forget the exact criteria I used, but I only looked at players with at least 100 races in their stats. After compiling a couple hundred sets of stats, I then looked at the average race lengths (total time divided by number of races).
The overall *average* race length was --- just over six minutes. Yep, only 6 minutes.
The highest average I found for a single individual was about 8.5 minutes.
Note that in FM2, there were no Hoppers --- the length of *every* multi-player race was set by the players themselves.
Now, if I'm Turn 10 and I'm looking at that data - typical user-created race is between 6 and 7 minutes, at most a couple thousand players active in long races - I'm probably not thinking "Oh, yeah, we should devote resources to developing a pit-strategies feature that will be used by less than 0.1% of our player base..."