Colin Baker was an excruciating failure as DW, routinely ranked dead last in fan polls and widely considered the start of the careening path to cancellation a few years later.
The best that can be said for it is that the idea behind the Sixth Doctor's unlikeable character wasn't terrible; but the actual presentation was not just terrible, but toxic.
JNT gives us an extreme Doctor, in the way that Rob Liefeld comics, Poochie from the Simpsons, and Mountain Dew Code Red are extreme: A crude version of the good stuff that equates being louder with being more awesome.
The obnoxiousness of the Doctor's personality might have worked better if they hired someone who could actually act, but all the audience got was horrible OTT pantomiming flaring nostrils.
You've posted that many times before. Not that I am having a go at someone for posting the same things of course as that would be very hypocritical, but I bring it up only in that it shows how in spite of all this Colin was the worst and everybody hates him, you can only find a very few sources online that absolutely trash him.
TBH I think its very unfair to pin all the blame on the actor. An actor is after all just one component. Like look at Missy. Terrible Master but its not a simple case of "Oh Michelle Gomez is a bad actress" She's actually a very good actress, but Missy sucks because its pandering, Gomez though good is miscast, her characterisation is terrible, and in about 90 percent of her episodes she was just crammed in there.
Colin similarly was let down by a number of outside factors such as poor scripts and being pushed to the side in some stories, but even then I wouldn't throw stones if I were a new who fan.
Its not like Colin ever had a story about a dweeb whose girlfriend ends up becoming a blow job slab, or one where the Doctor turned into a Gollum/Tinkerbell/Jesus/ hybrid who flew along on the power of luuuuuuuuuurve, or one where James Corden's baby beats up Cybermen, or one where the moon is an egg, or one where Trees save the earth, or one where the the Brig became a flying Cyber Zombie, the Master became a woman who wanted to fuck him, and the Doctor became the President of Earth.
Now I'm not saying that all New Who is as bad as that lot obviously. There have been some absolute classics over the years, but still you get my point.NOTHING in Colin's era even comes close to being as shit as that lot.