My understanding is that Tony Stark was initially created in an attempt to make a millionaire character that even hippies of the 60s would sympathize with, but I could be mistaken. Or hey, might be one of those nuanced things. If the attempt was to make him unlikable, well, it hasn't worked on me at least, even in the initial comics.
It's interesting to me to hear this opinion on Thor, considering that I adore him in the first two films. He starts out arrogant and unbearable, true, but that's part of his arc. He's had everything handed to him for the longest time, and when that's taken away, he has to build himself up into a better man who truly cares and is willing to sacrifice for the people around him. It is similar to Tony, but Tony's arc has more to do with internal issues with guilt that I don't think are entirely resolved in the MCU. And then Ragnarok happened and just obliterated Thor's character from the word go, but I suppose if you didn't like the first couple movies, you wouldn't mind much.
Not to say you or anyone should change your opinions, I just find it interesting to hear what seems to be a fairly popular view on the first couple Thor movies. And I like complaining about Ragnarok even though that's gonna get me chased out of house, town, and country.