One of the biggest issues with Roy though is that he is by and far the most lackluster unit you'll use. FE6 already has many mechanical issues: Thrones too strong, maps too large [this is somewhat subjective though] and weapons too inaccurate, coupled with wave after wave of sucky units with terrible bases and growths. You can cobble together a passable team, certainly, but you really have to struggle until the later chapters where Percival and Minerva descend from the Heavens to deliver thee from suffering until the good units roll in. Roy got saddled with super mediocre stats and growths; perhaps he can eventually become adequate but he'll never be an MVP like Ike, Lyn, or Hector or fulfill a certain role well (Marth in Shadow Dragon has a Rapier that unlike previous games can be forged, and thus makes a wonderful anti-cavalry unit as well as situational boss slayer, given gold). He must be babied, saddlebagged, carried across maps and eternally holding you back (even with his super late promotion) and that very heavily pisses me off. Roy is an albatross, foisted upon you in every map and given no way to redeem himself by the game's mechanics. Binding Blade probably revitalized the series because it introduced the FE GBA mechanics that have endured and been built upon in all future games, but most people and I personally cannot ignore all the huge flaws that bog it down, especially now that I have the future installments and far more stellar Lord characters to compare it to. And for all these reasons I will support sodding Walhart before I warm up to the idea of Roy in a Smash game. You can tell how ecstatic i was when I heard P:M brought him back instead of letting it die.
There are just so many more deserving candidates.