Please excuse my ignorance on this topic. - Why is this happening in the first place? - Who is this entity that grants a loose patent? - Why isn't this entity being interrogated ?
Because US patent laws and practices allow for it
> Who is this entity that grants a loose patent?
The United States Patents and Trademark Office.
> Why isn't this entity being interrogated ?
Because there would be very little point. One part of the issue is patent laws themselves, the other part is that the USPTO is taken to task for both overly lengthy examinations[0] and insufficiently rigorous examinations. I don't have much experience with the USPTO themselves, but knowing people working in european patent offices:
1. they are judged pretty much solely on the number of patents examined and their responsiveness
2. patent offices are funded through maintenance fees (fees paid to renew the patents and keep them enforceable) creating a fucked up incentive to accept patents by default at the cost of the already very loose and subjective patentability criteria ("novelty" and "inventive step or non-obviousness")
3. especially given patent offices are generally underfunded and short-staffed, especially in high-flying specialists able to actually evaluate patents which are either complex or in novel fields (being a patent examiner is few people's idea of a great career, even less so once you've built experience and respectability in your field, and that's assuming the patent office could even hire and pay you), even more so compared to the high-powered business they face
4. this is compounded by states routinely "diverting" (plundering) patent offices's funding, in the US Congress diverts about 10% of the USPTO's collected fees to the general treasury
5. it is also compounded by the opening of whole new and novel patent fields ("business method" patents) which generate even faster growth than the historical patent fields and are the source of much of the bullshit patents
that's not even considering that the existing patent system simply isn't a good fit for software, more generally the whole field of business method patents seems incredibly fucked up and created specifically to be abused (good thing europe has declined to implement it)
[0] https://en.wikipedia.org/wiki/Backlog_of_unexamined_patent_a...