Mako Garei, pastel drawing by chef kaz matsune
(originally posted on Quora.com)
On top of the price, quality and family friendly environment (including less interaction with sushi chefs), many Kaizen•Zushi chains now offer variety of non-sushi dishes which seem to attract more and wider range of people from the young to the old.
Sushi•Ro's website says that they offer over 80 dishes now. Plus their drink menu is as good as any family restaurant and dessert menu is packed with kid's favorite like ice cream and pudding.
Just looked at the noodles and other dishes at Sushi•Ro here.
You can just go in for noodles without eating sushi and no one will tell you that you need to order their sushi!
Lastly, they keep introducing new menu including sushi and that is the key to their popularity because Japanese love new things.
("Overfilled" Salmon Roe from Hokkaido, "Large Cut" Salmon Nigiri, "Thick Cut" Tamago/Egg custard, etc.)