That’s fair comment. On the OP :- as an Irishman, who currently employs a Scottish guy, I would say Doohan’s accent was fair to excellent. If I’d been told after watching him that he’d grown up in Scotland, I’d believe it :- so would my Scottish employee.
I personally would not go that far. His accent was always a joke in my family as I grew up - we would have known pretty quickly he wasn’t actually Scottish and we laughed out loud when we saw an interview with the actor when he said he tried to make Scotty from ‘Aiberdeen’. A similar example is Paul Whitehouse’s Scottish accent in some adverts just now - non Scots might think it sounds real but we’re not fooled.
People who can do it right include:
Emma Thompson - everyone thought she really was Scottish when she first appeared in the TV series ‘Tutti Frutti’,
Johnny Lee Miller in Trainspotting,
Mike Myers in various things (I love the dad in ‘So I Married an Axe Murderer’.
No, I was woefully ignorant.
You and Google have set me straight.
I apologize if I gave offense.
Heid! The dad in “So I Married an Axe Murderer” was pretty much perfect (and scarily like my dad), as are your other two examples.
The guy who plays House (don’t watch the show, so don’t know his name) did a few episodes of MI-5 (Spooks) a few years ago, and his accent was pretty good. Caught him on So Graham Norton too, and he kept it up there as well. A joke on English viewers?
(How many heads just exploded?)
Really? Mike Myers always sounded like comic opera Scottish to me. But I guess his parents are authentic.
Hugh Laurie. I don’t like House, I’ve liked him in everything else he’s done.
The dad character was really very good, partially because what he was saying was pretty authentic. Caricature, for sure, but not all that much…
The good people of Aberdeen claim Scotty as their own, and they have some ST canon in their favor: Aberdeen | Memory Alpha | Fandom
And, of course, his French brother, French sister-in-law and young French nephew have the same accent as he does, even when they’re alone together in, y’know, France: Family (episode) | Memory Alpha | Fandom
With the way communications are now and as easy as it is to move around it is getting harder to pick out the pure accents from the fake ones. There is a lot of mixing and homogenizing going on.
I am from the Southern part of the US and in the past we had always been forced to put up with the absolute worst caricatures of our accents it is possible to imagine. But recently they have been getting better. “Justified” on the FX channel is an example. I was able to pick out that Boyd was a natural Southerner. Raylon’s accent was one of the worst ones. But they were all passable if you allowed for the fact that there is a lot of variation now. The actor who plays the chief doesn’t have a thick accent but it sounded authentic if you allowed for the fact he may have tried to mainstream his accent a bit since he was in a position of authority. The actor who plays him is from North Carolina and has probably had to sublimate his accent quite a bit in the acting business.
One mistake they make a lot is thinking a Texas accent is the same as a Southern accent. It may be a subset but it is distinctly different. Where I live you can even tell whether someone was raised in the country or city by their accent but that is changing quickly now. I would be extremely surprised if something similar wasn’t happening with Scottish accents.
Definitely the latter. Have you heard some of us speak? 
It’s not by any stretch of the imagination a good Scottish accent, but neither is it particularly offensive. It’s someone who’s clearly not Scottish trying an accent and not making as big an arse of it as they might be expected to.
In the grand scheme of attempted theatrical Scottish accents that ranks it pretty highly I think.
Yep, I’d have to agree with this. Russ Abbott it ain’t.
Patrick Stewart is actually a Yorkshireman by birth (Mirfield). He ruefully admits that he had his original accent beaten out of him long ago during his training, and all he can do now is stage-Yorkshire.
Apparently his dad is Scottish, hence him being rather familiar with the accent & good at it 
Yes, Amy made a rather big deal about being Scottish in the first two episodes. She was rather proud of the Scots for having their own spaceship (and not torturing a spacewhale!) in The Beast Below
I read his autobiography. He said he got the accent from listening to the real thing He just intentionally modified the accent to be understandable by an American audience.
Except his brother, wife and kid. But, they were very much traditionalists, so they may have also held on to the accent. And Picard had a French accent as a boy (being played by the same guy as his nephew.) And he grew up in the same conditions. He must have acquired the “proper” French accent as he grew up.
Yeah, I’m fanwanking to make your fanwank work. I like it!
But his French is atrocious, too. He ought to be able to switch back if he’s so good with accents. The fanwank by silenus and me works better.
See above. You can make it work if you fanwank hard enough!
Or maybe this happened to Picard, too, for whatever reason. Heck, maybe he volunteered for this treatment so he wouldn’t slip into the old accent of his youth. Or maybe there’s technology in the future that allows you to change your accent. It would be related to the Universal Translator.
Amy Pond was Scottish, but moved to England (wherever her house was) at a young age. The Doctor made a comment about her keeping her Scottish accent even though she was so young.
Hugh Laurie is British. His House accent is a fake American accent. He does very well.
Is that what Rhythmdvl meant? It never occurred to me that anyone could think that Hugh Laurie is American. Are we sure he wasn’t kidding?
James Doohan is Canadian, isn’t he?
I know that some areas of Atlantic Canada are heavily Scottish, and I did hear some Scottish-sounding accents there.
Canadians, does Scotty sound anything like a Cape Bretoner or a Prince Edward Islander?
Yes, he was (he died in 2005). Wiki says, “Doohan was born in Vancouver, British Columbia, the youngest of four children of William and Sarah Doohan, who emigrated from Bangor, County Down, Northern Ireland.”