I've just started on atorvastatin, and am happy with the choice I've made. I read as much as I could about statins on reputable websites (ie heart charities, diabetes UK, plus some research papers I found via google scholar), and balanced the potential side effects against the potential benefits.
I wasn't under pressure from the GP to take them. I was offered them a year ago and said no, as I wanted to try lifestyle measures first, as the NICE guidance suggests I should. A year later, my lipids were worse, so I asked the GP at the medication review, and she put them on my prescription. If I'd not raised statins with her, I don't think I'd have been offered them, as we'd mostly talked about diabetes medication.
I'm also relaxed if the GPs are incentivised financially to prescribe them, they're financially incentivised by NICE to do other things which are beneficial to patients, ie diabetes reviews, health screening for women etc.
As for a link between dementia and statins, I've looked for this in google scholar, and found a
metaanalysis which says "In total, a pooled analysis of 36 studies found that
statins were associated with a decreased risk of dementia (OR 0.80 (CI 0.75-0.86). " from the European society of cardiologists.
There's lots of "woo" about how bad they are, yet they're massively widely prescribed. At worst, if you take them and have bad side effects, you can stop taking them. At best, they prolong your life with a better quality of life, as you have a reduced risk of heart attacks and strokes.
Ultimately, I support people making the right decisions for their own health, be that taking statins, or not taking statins, as long as it's an informed decision after speaking with health professionals.