They're just not strong enough for my liking bud. That said, I'm a Nene Valley chap so have to deal with serious weed on most waters.
Dude - My experience, as QA Manager for a manufacturer of heat treated carbon steel fasteners (the same process used to make hooks) for the automotive industry, tells me it's a fact that if the yield point is exceeded even once, you've weakened the hook significantly - spring rate is compromised so the hook cannot absorb shock as intended. Therefore when stresses on the hook reach a certain level the hook WILL bend rather than flex - it's just a question of whether those stress levels will be reached while the fish is being landed. I'm not saying you can't land fish on modified hooks (as you say, plenty have been landed), just that IMO it's not worth the risk - it's asking for trouble fella.