There is also, I think a very big difference in how and IF works and a regular videogame works. If we take an rpg, which is the genre most of us think of when it comes to video game romances, then it very often have a hub-structure where you can interact with the NPC at leasure and which takes place in a space where we have an eternity to act. It also rarely matters if you choose to do the interaction the first, fourht of fifth time you are physically in the hub.
Few text based IF have that hub (I can think of a few, which do.) And if they have a hub there is often a limit on the number of interaction you can do and even if that is true recalling how many interaction and how far along you are on the interaction tree happens even less. Which means that you have one chance for once interaction or else it is goodbye forever to that specific interaction. The reason for this is that these projects is one person projects and the number of variables you have to keep in mind if you don´t can quickly become overwhelming. Non-linarity can quickly ballon and it is much more simple to have a check which say - did x or y happen with only one option for x or y to happen.
If you want an example of where there is a mini-hub then shephards of haven, does do that. There are small intermission, so to speak where you choose between who you hang out with and other activities. But shephard of haven is shaping up to being a big game.