Well this was to be expected once the system had its official reveal.
The Switch's success is not dependant on huge third party games which already exist on PS4/X1. Sure, it would "help" but it would also help if the PS4 had GTA as an exclusive or had Mario Kart and Pokemon on the platform.... yet none of these things are necessary for it to be a huge success as we're seeing.
If Red Dead Redemption 2 was on Switch, 90% of the games audience would completely ignore the downgraded Switch version. I don't know why people continue to force certain points without contextualising them to what the Switch is (a handheld/console hybrid) and how Nintendo can expect to find an audience.
For now I think they're targeting young adults who are either gaming nerds (already own PS4 or X1) or fringe gamers (aren't yet interested in PS4/X1) and Kids. A consistent output of Nintendo best and biggest IPs this year is their main requirement. Past that and past 1st party support I think Japanese devs moving on from the 3DS, EA being consistent with sport titles and Ubi taking the lead with unique/original western content are the main concerns for them appealing to their target audiences. Having mega brands like StarWars/GTA/COD present on the platform in some form is ideal, general multiplatform support is just the cherry on the top.