If the legislation hadn't been passed in the Finance Act, no one would think anything of this other than a cool way to pay less tax, which is exactly what it was. A loophole, that has legislatively now been closed.
That just isn't true, people have been using this sort of tax dodge way before then and HMRC has been taking people to court for offshore employee trusts or family benefit trusts for over a decade now.
If you're say a senior trader and your firm says "hey we can reduce your tax bill by making loans to your missus from an offshore trust" then you'd be silly not to go and get independent advice from an actual chartered tax advisor... if they'd not heard of the sorts of cases that have hit national newspapers then I'd be surprised. They'd generally know there was a risk there (of HMRC disputing the scheme - I'm not saying they would have been able to get a crystal ball out and predict some future means of enforcement like a loan charge but that isn't relevant, important point is the risk that you'd have to pay the tax you are deemed to owe and therfore budget accordingly if you still go ahead with it.) I don't doubt that some schemes had an "accountant" (whether chartered or not) involved, I don't doubt that there might be some shady financial advisors out there with an interest in flogging dubious schemes. This is why seeking independent advice from an actual tax professional not just any random "accountant" or "advisor" is a good idea!
The tribunal on EBTs found that disguising income as loans as far back as about 2001 weren't legitimate, it was the entire basis of HMRC v RFC, RFC had stopped using them by 2009 when they realised they were on shaky ground (as did other football clubs - many of them deciding to pay up when they realised their "mistake" and HMRC came calling).
I know the company my friend was at used them through the 00s, I also remember him telling me about some old scheme, before his time, involving platinum sponge. These firms know that they're taking the mickey a bit, the beneficiaries know they're taking the mickey, they know HMRC will take action at some point, they're basically just betting that HMRC will stop it going forwards and that they'll be able to fight to keep previous gains.... the risk is there though that they will have to pay up, they know that and they're openly taking that risk.