As a design choice, that makes sense to the extent of a "default", but when we select to change it (as the game allows), that should become the new default until otherwise changed.
Beyond that, the design choice doesn't take into account that spawn points are different for when a sim is coming home vs. when a sim is invited to the lot. My main game is played on the big windenburg lot - the spawn point for sims invited over is so far away it takes them an hour in sim time just to get to the house, and then they have to walk all the way around to the "front". I don't care if my sims spawn not next to the front door, because they don't care what is the front door. But visitors are pretty insistent on going to the front door, so it can take ages in game for them to actually show up. I flipped the house and then set the proper front as the front, but then because of this design choice, every time I open up the game I have to reselect the proper front door, which half the time doesn't even seem to work right.
I would recommend either adjusting the design so that it actually sticks, shifting which spawn point is used, or adjusting the spawn points to be the same for visitors as sims. Or a combination. Sims already take soooo long to do things, they often take forever just to start doing what you ask them to do, and this trifecta only adds to the frustration since it further limits the in-game time with the visitor and I doubt anything will be done about the issues with in-game timing and sims taking half an hour in game just to start something you told them to do.