he's answered it in the past. (Destiny)

by General Vagueness , The Vault of Sass, Sunday, June 21, 2015, 21:42 (3682 days ago) @ Claude Errera

Turns out the ability to have multiple characters, but not feel obligated to keep those multiple characters on the cutting edge, is not a universally-held one.

Well even if you do feel like you have to keep them all at the top, it's not like it's hard, you just play and receive stuff or buy stuff. You don't even need to play as your other characters to get class-specific armor for them. The only way I can see it would be a problem is if you don't like Destiny's grind, and if you don't like that then you probably already checked out.