Herblore used to be my favorite members skill. This was back when I thought flesh crawlers were, to put it bluntly, the shizzle. My Herblore was actually my first ranked skill, at 30. I was so proud, I decided to devote my life to the money sionk.
900 total levels later, I've gone up 16 Herblore levels. What happened?
First of all, the skill's monumentally expensive. It was 200m before the recent update. It'll probably be 250-300M now. Even if you do things the slow way and make Serum 207's, it's tens of millions and slow as a dial-up while sitting in W1 GE. Well, maybe that's not true. But it's slow that way. You can make profit doing herblore too, if you farm and kill for your herbs. Sadly, opportunity cost rears its ugly head and roars, belching it's vile spew all over you. The difference between farming herbs and selling the herbs and farming herbs and selling the potions is the difference between an Armadyl Godsword and a Mithril Dagger (p+).
Second of all, the skill was useless for me. I didn't make prayer pots when I needed them- I bought them. I don't make my own worthless regular pots when I can just buy super pots off of the GE. I'm certainly not going to spend money to train a skill (I spin flax for crafting, I smelt bars for smithing, I don't do construction. This would explain my 1517 total level.)
Third of all, herblore didn't provide a "chase" type reward. Mining was boring as crazy. At 85 it becomes a nice little money maker. Runecrafting is like Mining, only slower and more boring and with a little profit in between. At 91 it becomes some of the best money in the whole game. Hunter is crap > 70 or so. Magic's got Ice Barrage. Slayer has Abyssal Demons. Construction has Gilded Altars. Prayer has Piety. Fishing has Rocktails and Cavefish. The only other skill that doesn't have this type of reward is Smithing, which in my opinion is the worst skill in the game. (I'll exclude crafting because battlestaves are useful, and cooking because cooking takes 3 hours for 99).
One problem down, one problem exacerbated, and one skill that's still totally useless for me.