Because emulating stuff on the Switch doesn't seem to be something for you at all.
Almost everyone in this forum owns (and likes) a Switch. That means is the most recent console for us and will be still in use for the next few years while PSP, Vita und most likely even the 3DS will start to collect dust at home. So why it is so hard to understand that we want the Switch to be capable of everything that the other devices were able to do as well so the one device (the Switch) we carry with us all the time does the job?
That's what made smartphones so popular: Having many things in one device.
Now we want the same for gaming: All (or at least many) gaming systems in one device.