Switch certainly isn't selling similarly to 3DS.It seems you can't see that Nintendo Switch is selling like most Nintendo handhelds. No one really really thinks it's a serious under the TV console. It's nothing more than the follow up to the 3DS in all but name and like most Nintendo handhelds its sells loads and makes tons of cash.
Comparing the sales in the same timeframe between 3DS and NSW (first 50 quarters).
Note that by this point in time 3DS sales in the following fiscal year ended up at 6.79M whereas Nintendo's forecast for the current fiscal year is 25.50M of Switch consoles sold.