I can think of 9 skills off the top of my head that only have gm. If i would have to 120 all those, well i would probably just never do it. Or if i did, when someone wanted something made they definitely wouldnt get it for free anymore, would have to pay for all that grinding.
I really dont even know what potions your talking about. I stopped making potions a a long long time ago, when 10k for a keg became very very affordable.
I guess you mean the higher end ones like darkglow poison and the like? No one uses those. If new ones were introduced, and actually usefull, then maybe, maybe i would 120 it.
i like gm skills, wish all skills were still gm. It would allow alot more templates.
(except for imbuing that skill should be around 200 to max as it killed the need for most other crafting skills, and essences drops should be on par with a minor artie drop)
So yeah, 120 alchemy, nice to think about i guess, but i think its fine at 100