I can’t believe some of the people in this thread, lol. I agree completely that working on making yourself attractive is better than pigeon-holing one person towards you, but his warnings of “backfiring” are not just a sign he’s a “bad magic worker”, in my opinion.
Love is fickle and testy. One day you want someone to love you, the next they are obsessed with you and you are genuinely frightened. It’s a “Careful What You Wish For” kind of thing. This isn’t reflective of someone being bad at manifesting their desires, we just sometimes bring in things we don’t need.
There are boat loads of posts on this forum of people expressing discomfort at the kind of love they felt after preforming love spells. In my honest opinion, I don’t think any amount of skill can prevent this. But a skilled magic worker would likely be able to amend the situation with little issue after it arose. It’s still full disclosure with the OP about potential consequences of their actions. It’s not moralizing or sign of weakness, it’s acknowledging that there are consequences for things you do that you may not realize in the moment.