As a female sub-elite marathoner, I love doing race-workouts. Let's say for instance I have 20 miles with 12 or so at MP on the schedule. I have the choice of:
a) creating a route, hiding/carrying fluids, pushing myself to run MP by myself around dog-walkers, tourists walking 7 across, and cars
b) doing a 7 mile warmup to a half marathon, running at MP on the road without having to worry about obstacles, having fluids handed to me like they will be in my marathon, practicing running in the race environment wearing my uniform and finding the correct pace, getting cheers and crowd support, and even potentially winning some prize money! And then I get to hang out with other runners from the community and catch up.
That's an obvious choice B for me. I have often done an 18 mile "warmup" to a 5k, or 10 mile run to a 10-miler. Racing is always better than working out solo, and while I usually go faster than "tempo" pace for my race efforts, I think practicing pacing in an exciting race environment with people yelling at you is especially important for marathoners.
And while I may write "MP race simulation" or something like that on Strava for my teammates, I would never say "just tempoing" to anyone at the race. If anyone says "nice job!" or "great race!" I would just say "thanks! what a beautiful day!" or something like that.