I wonder if there are reports from any actors/crew other than the secondary TOS cast?
I mean, if the guy is an egotistical jerk, wouldn't somebody else have noticed somewhere down the line?
They have. You catch enough folks on the convention circuit - guest actors on TOS, some of the new cast in the Bennett-produced Star Trek movies - and they've said similar things, from the dismissive attitude on to line hogging/counting, etc.
Keep in mind that bitter actors use this Shatner myth to pad an otherwise blink-and-you-missed it career. The most notorious of this lot was Doohan, Takei and Yvonne Craig; take away the Shatner BS, and what do you have?
"uh, Scotty had more lines in that episode! I shoulda, coulda, woulda..."
Whatever. Shatner was not Roddenberry, Desilu, NBC or the series' sponsors--the only agents (individually or collectively) who had the influnece to change an actor's position (fate). 1960s TV had a pecking star order, and Doohan was #4 at best. If someone with an inarguably more important role--such as Batman's Burt "Robin" Ward--was occasionally shortchanged in the line department (and during the era, Robin was crucial to the Batman image / franchise), what made Doohan assume he needed to be elevated beyond his level?
Shatner did not create Scotty, nor was he responsible for how the star/series system worked.
Takei: "oooohhhhhh Shatner was very democratic, but not fair where lines were...blah blah..."
Bonk, bonk, bad kid. See the Doohan analysis.
Yvonne Craig: no career worth mentioning, other than that she played a signficant role in the death of the Batman TV series...so i'm guessing she's not going to go into too much detail about that. On the other hand, she feels the need to talk crap about a man she did not know on a show she spent all of what--a couple days on at best? Yes, that's all one requires to make character assessments repreated over the span of decades as "fact."
Some cannot accept their limited position in the annals of entertainment, and if there was ONE--just one lesson they should have learned back in acting school, it was the fact everyone is not going to be a star, some will be more successful than you, so there is no "level playing field" in a business about perception and ability.
Shatner had ability not lost to anyone watching him, starting in his early years in Canada, and certainly when cast as Kirk. If Doohan--through the force of his performances--scored some major hit with audiences on a Shatner level, producers would not waste any time trying to milk him--its to their benefit to do so--but that did not happen, as he (like Takei) was not "that guy."
Bitter pill, but eventually, the taste goes away, and the medicine is accepted.