1-The portability gives a nice extra reason to buy those titles. Unlike on consoles like the DS and the 3DS,if a multiplat got ported to the system it would basically had to be a totally different game since it couldn't run the same as the home console. On the Switch however,while the system is weaker than the rivals,the gap is not as big as previous handhelds, so it can run basically the same versions with lower specs.
2-Nintendo this time is actually trying hard to market those titles,featuring them on directs,events and such. The majority of videos and commercials of the console during the first year had Fifa 18 and Skyrim for example.
3-The console is selling really fast and unlike the Wii the crowd this time doesn't focus on casual games that much when you compare. The Wii sold really fast but a good part of the buyer where looking for Wii Sports/Fit/Play sort of titles, on Switch the audience aren't getting distracted by titles like those leaving space to the other games.
Switch Friend Code: SW - 1286-0025-9138