No, they're definitely right.
Crafting is ridiculously easy this expansion. Recipe difficulty was reduced, the toolkit was simplified, materials are easier to obtain, EXP was practically tripled and Ishgard added an easy way to spam collectibles for that exp. As a result, a large number of players who previously had no interest in crafting have a maxed DoH now (even if they still don't particularly enjoy crafting). So competition on the markets has skyrocketed while at the same time most players are self-sufficient so demand for crafted items has dropped.
That doesn't mean bots aren't an issue. They exist and are a problem, but they aren't the entire reason. The changes to crafting has also indirectly made botting far more viable due to easily leveled and geared crafters, easy to bot mats, easy crafts and cross world markets. It's a far more simple matter now to obtain a maxed DoH and jump straight into mass botting.