Arena went out of its way to paint the Gorn as responding to Federation incursion into their territory, and to show that they were similar to humans in a number of ways, not just mindless aggressors.
It showed they were calculating hunters. They analyzed evaluated and TESTED their prey. It also showed they were not interested in peaceful diplomacy. In TOS S1 - "Arena" it's abundantly clear they have A LOT of info about the Federation; and understand Federation language to the point that they not only send a convincing signal to the 1701 - which they seem to know is the main patrol ship as they sent the signal directly to the ship when it's two days away and convincingly faked the personality of Starfleet Commodore Travers, right up to the point Kirk and Co. beam down to find the base obliterated...
In fact (and remember Commodore Traver's dialogue is ALL Gorn created):
http://www.chakoteya.net/StarTrek/19.htm
TRAVERS [OC]: Travers, Jim. We're waiting.
KIRK: Good, Commodore. We're on our way.
TRAVERS [OC]: Be sure to bring along your tactical people. I've got an interesting problem for them.
KIRK: We'll beam down immediately, Commodore. Kirk out.
SPOCK: Captain. I wonder why he's insistent that our tactical aides come down.
KIRK: This colony is isolated, exposed, out on the edge of now here. He probably wants additional advice.
SPOCK: Perhaps, Captain, but nevertheless
MCCOY: Spock, isn't it enough the commodore is famous for his hospitality? I, for one, could use a good non-reconstituted meal.
SPOCK: Doctor, you are a sensualist.
MCCOY: You bet your pointed ears I am. Ready whenever you are, Captain.
(Six men, including one red shirt, get on the transporter platform)
KIRK: Energize.
^^^
So yeah, calculating hunters appraising prey.
In the episode the Gorn also respond to the Cestus III base's offer of surrender (including being informed that the base has women and children by "pouring it on", per the one survivor's own account; and destroying the base - THEN luring the 1701 to the base to further test their military capabilities.
MAN: They came in space normal speed, using our regular approach route, but they knocked out our phaser batteries with their first salvo. From then on we were helpless. We weren't expecting anything! Why should we? We didn't have anything anyone would want.
KIRK: Easy. Easy.
MAN: They poured it on, like, like phasers, only worse, whatever they were using. I tried to signal them. We called up. Tried to surrender. We had women and children. I told them that! I begged them! They wouldn't listen. They didn't let up for a moment.
KIRK: Lieutenant, the Enterprise received two messages, ostensibly from Cestus Three. One for the Enterprise to go there, and the other for myself and my tactical crew to beam down to the surface.
MAN: They hit us a full day before you got there, Captain. No messages came from us, Captain. Why did they do it? Why? Why did they do it? There has to be a reason. There has to be a reason!
^^^
Which also shows that even after having all that info regarding the Federation and Starfleet and full contextual understanding of Federation language - the Gorn still choose to hunt and kill prey rather then inform Starfleet that they consider this area of space Gorn territory and pursue some form a non aggressive diplomacy.
A big highlighted difference is that it appears the Gorn do not attempt diplomacy even if they have the knowledge needed to do so. Their first response seems to be to hunt and kill intruders.
That's a HUGE difference between the Gorn and the Federation as even in TOS the Federation is consistently shown always trying to use peaceful diplomacy first; and its members only resorts to force if diplomacy fails/is refused; and force is always their last option.
That said, I had no issue with Kirk's reply as the Gorn did keenly demonstrate they DID know how to communicate; refused an offer of surrender even after being told women and children were on the base, and instead COMPLETELY wiped out said base. Then afterwards they went out of their way to lay a trap to test Federation military capability.
^^^
So yeah, they do not come across here as just a peaceful race who misunderstood Federation intentions and reacted poorly. They were truly just cold blooded hunters (in more ways than one

) out to eliminate what they saw as prey entering their territory.