Spin support is beneficial for any Pokemon that doesn't have magic guard. However, spin support can be more beneficial to some pokemon than others. While Ninetales doesn't "need" spin support absolutely, his weakness to rocks and vulnerability to the other forms of hazards make spin support greatly desirable for him. If you're making a sun team, you'd probably have at least one other fire-type pokemon on your team and would also greatly appreciate spin support. Just because you don't plan on switching Ninetales in a lot doesn't change the fact that he's weak to stealth rocks, a disadvantage that none of the other OU weather starters have. Being on the A-rank tier is good. Clearly not as got as A+, but it's still good. Ninetales is a good pokemon, but when compared to the other OU weather starters, he kind of falls flat. His typing isn't so good for defense and his stats are decidedly mediocre. Ninetales may be fast, but as a weather starter, being faster isn't a good thing and he's the fastest weather starter there is. That means that when facing an opposing weather team, they'll always be able to get their weather up first turn. Ninetales has some supportive moves, but then again... you'd have to have a very barren move pool if you didn't have at least a couple supportive moves. Ninetales is most defnitely not better than Politoed. Politoed has better bulk, better Sp. atk, better typing (meaning no weakness to stealth rocks), and arguably a better move pool.