I mean I don't really want to get into a which-is-better argument, but TMS really seems so lazy in its characterizations. They're fine and inoffensive, but having played it twice on Wii U, they clearly just went for the safe anime tropes for each one of them. Growth arcs don't really exist, events in game don't really affect personalities, even motivations are paper thin. Not saying Persona doesn't also suffer with some characters and overall story in the second half, but there's more care and thought put into a wider range of characters for a longer time. It all comes down to scope, budget, dev resources/time at the end of the day. TMS is a lot lower budget and lower priority for Atlus/Nintendo and you can tell.