Their being older does not mean they're better, yes, but it's certainly at least a major factor to consider, as is the fact that Xbox has never achieved market dominance, where Nintendo has thrice (not including their consoles pre-NES) and Sony has also had market dominance thrice. Of course, quality is the important thing here, but you do also have to take a look at their legacy....
@Salladwold: Sure, Nintendo has been in this longer, but that isn't the main reason people chose Nintendo over Microsoft and Sony. A few of the reasons are shown below:
.They care more about gameplay than graphics
.They have changed gaming as a whole. (Ex. N64- 3D gaming, Wii- Motion controls)
.They have very good games
.They have made some of the best handheld systems ever made
.Free online services (or close to free with the Switch)
.They have the most well-known 1st party games (Ex. Pokemon, Super Mario, Legend of Zelda, Kirby)
. No matter how much you try to prove they didn't, they are the reason most games in today's day and age exist.
So, as you see Salladwold, nostalgia is not the only reason people choose Nintendo over the other opponents. Nintendo has supplied people with entertainment for years and they haven't stopped yet.
If we're talking about consoles, sony gives me broken games, microsoft gives me broken software, AND OH LOOK NINTENDO HAS LOGIC AND MAKES WORKING SOFTWARE AND GAMES WOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOW