Well, I'm not opposed to banning it relatively soon, just not yet. It's been 2 days since release and people are already calling for bans, that's ridiculous. The metagame is hardly developed and a lot of people are still subject to shiny new toy syndrome, meaning more hesitance towards using older mons who could counter Pheromosa quite well.
Arcanine for example is an actual counter to Pheromosa. Able to survive 2 Hi Jump Kicks from LO Pheromosa with the right investment and easily kill back with a fire move or ESpeed if it goes for the U-Turn. Also limits Pheromosa from Dugtrio trapping since Arcanine OHKO's with Extremespeed.
Mantine is also capable of stopping Pheromosa thanks to it's new +20 HP, it can switch into any of Pheromosa's attacks and KO back with Air Slash. Nor is it trapped by Duggy.
I understand that 2 counters don't make something unbroken, but it's VERY difficult for pokemon to get unbanned once they're gone. I would like it if we had some time to make a more educated decision on Pheromosa's capabilities before we attempt to send it off to uber's, that's all I'm saying.
Edit: Forgot Mantine is currently unavailable, but I feel like that kind of strengthens my point. The meta we're currently dealing with is a very temporary one, and making bans based on it is short sighted. Unless we plan on retesting every mon we choose to ban until then, it's probably best not to ban any. (Except maybe Zygarde, that thing is absurd)