Yes. Single elimination tournaments have high stakes. If you lose once, you're done. The NBA can have a team loose 12 times in the playoffs and still win a championship. So each game has pretty low stakes.
Depends on perspective.
There is no doubt that there is more pressure in single elimination tournaments. However, it's also over very quickly. In a 7 game series, the pressure builds gradually until you reach the point of an elimination game.
So, you get the buildup, then you (hopefully) get a game 7 which can actually have more drama and excitement because of the build up to it. Also, if you're lucky, you get situations like we just had with the Nuggets where a team gets behind 3-1 and then comes back to force a game 7. Those are fun because you have what looks like a series that's over and you end up getting the drama of 3 straight elimination games.
Also, while we all love underdogs and the upsets that can happen early in single elimination games...ultimately people want the 2 best teams in the finals. 7 game series tend to do a much better job of ensuring that outcome.
And of course, as @shopson67 mentioned, there is the money. The league would lose millions in revenue with a single elimination tournament.