I get why they tried something different, has its roots in the history of rally and plenty of road rallying that goes on now, historic and otherwise.
It just doesn’t translate that well to a game, was interesting the first few times, but once the achievements were done, no reason to really go back to it.
I’m not sure it’ll have taken away dev time from a free roam, most of regularity rally’s implementation will have been just reconfiguring driving criteria, I.e average speed and finishing sectors within set times.