probably not.

Which 121 operations are bad in the U.S.?

Honestly, I wouldn't feel comfortable accepting the responsibility of transporting a large number of passengers with less than 1,500 of relevant training/experience. As a newer guy into the industry, I take my role very seriously in trying to do everything I can to learn everything I can to be a safe and competent as possible and I plan to I never allow myself to become complacent. The day I stop learning is the day I retire.

To me, 1,500 is where the competency level (and commitment to actually work to get there) is the BASE starting point for being responsible the lives of the paying travelers behind me. I am glad that the 1,500 is there and I hope it sticks around. Shortcuts aren't the way to go for a job where a simple mistake can cost a great number of lives and cost hundreds of millions of dollars in damages (insurance, medical costs, and litigation that follows).

There are people who build 1500 hours of experience, and then there are people who build the same hour 1500 times. Putzing around the pattern in a 172 for 1500 doesn't do much for your abilities to be in control of a transport category jet.

Much better way to lower the 1500 hour requirements would be to allow restricted ATP to people with 135 experience. For example, 1000 hours, with 500 hours of 135 operation, or some other number like that. The lowered hours for 141 school grads makes no sense at all - it's obviously lobbied by the Riddle people.

I agree that there is definitely a difference in the way you build hours. And hour flying X isn't necessarily equal to an hour flying Y. I think that discussion I saw posted on here by ER concluded that pilots that just drill holes in the sky to build hours tend to underperform to pilots that attend regimented training programs or instruct as an example. This makes sense to me. I could tear it up in a cheap 150, but if I'm alone and flying just for the sake of flying, my skills will probably not improve as well as if I was teaching updated standards to a new student. Yadda, yadda, yadda.

Well no one has that responsibility at 1500 hours, the PIC is the one with the responsibility.

Exactly, the 1500 hour rule wasn't about safety, it was about politics. And one could even make the argument that it makes us less safe since some things mentally atrophy when one is doing diver driving, photography, or patternwork. How many survey pilots use their IFR skills on a regular basis for example?

Yes, you're correct technically... the ultimate responsibility.