I think the apostrophes are a lot of shorthand for look, ma, it's an alien!
There are a ton of doubled a's, too.
To dovetail with the above, there's dialect and then there's not respecting characters' intelligence. And there's also just plain getting it wrong.
Trip Tucker, for example, is from the northern Florida panhandle. This is near Alabama and so a speaker from there can get a bit of the Alabama sound, plus Tucker is educated (I don't buy the nonsense that he didn't graduate from college; Engineers aren't mere tinkerers. It's a profession analogous in many ways to physicians and attorneys) so he was likely in contact with a lot of different people with varying ways of speaking, or he may have attended school outside of his home town. So there is a little bit of a twang and occasional g's are dropped (darlin', goin'
) but not all the time. He also occasionally elides sounds, e. g. kinda, woulda
, etc. Plus not all Southerners sound alike, and they don't just pepper their speech with a ton of y'alls and then the writer can call it a day.
Same with British/Irish/Welsh/Australian/New Zealander speak. It differs, and I think it makes sense for writers to listen for subtleties and even listen to interviews with actors from these various places in order to get a feel for the sounds. But again, British characters don't necessary speak in a super-posh manner all the time.
Further to the point, word choice can often convey more about an accent than dropping a bunch of apostrophes into the mix. Someone who says prior to
instead of before
is going to sound more educated and precise, usually. But of course it can be overdone. Spot is a cat
. Calling him a feline
is, except when Data says it, overdoing it. And even Data calls him a cat
a lot of the time.
PS Re the overly complex character names - amen! If a name is long, that character had better get a nickname really, really fast.