Corruption and undue political influence stemming from a large source of extractive income isn't a an issue particular to Islam as I can see it; in fact I'd say it's something endemic to the human condition.

But, when it comes to oil production what I would say is that due to the overlapping geography of the foundation and consequent spread of Islam and largest and easiest to extract oil resources in the world being very large combined with human tendency to overfit pattern matching that it is all too easy to see why some would conflate the two.

But Islamic majority nations aren't the only "oil countries", and not all "oil countries" are corrupt (but I'd guess the overwhelming majority of "oil countries" are corrupt, not least because of Dutch Disease).

Your sentences are quite difficult to read so I apologise if I'm misunderstanding, but I think it's good to remember cases like Saudi where religious fundamentalists were placed into power by Western powers. These days we see them as representative of the Islamic world but it's largely our own doing.

I'm aware that there are non Islamic "oil countries" of course and I don't think the GP comment was equating oil with Islam. It's just something that does happen in other contexts and that we should be aware of when speaking, because there are very real real would consequences.

Big money from resource extraction is always boom/bust and always struggling with corrupting influences. The folks who control the political strings are always flush with cash, and their only priority is maximizing return on their assets.