That doesn't sound like a good example of turn limiting, in fact it sounds like they wanted to have a limit and then had to come up with an excuse to impose it. Note, I've only played the original XCom/UFO games and never felt the need to play the new ones so I'm only going on your description.
*nods* That particular mission is probably one of the better scripted missions in XCOM1 I feel. It is a mission which I do enjoy a lot actually. It was always a mission that most players, who had encountered it befor, would dread to have to deal with once it popped up... and people who had never encountered it befor where in for a pretty nasty surprice when they got there.
It was at a fishing village, and at first you encounter loads of zombies, but then further in to the mission the main enemy was revealed... Chryssalid (do you remember those? They look different in XCOM, but they are still really nasty opponents, and like in X-Com/UFO they would always be the enemy I focus on first when ever they show up), and an absolut swarm of them to. And not only that... a few of them where spawning out of dead sharks hanging in the harbor, which was not actually the worst of it. Because when you reached the huge ship which has rammed the harber/shoreline, you find that there is a huge whale in the ship, and to your horror you start seeing Chryssalid spawning out of the Whale, and it's not stopping. At which point the mission is scrubbed and XCOM decides that airstriking the whole village into smithereens is the best way solve this problem... so your given 8 turns to not only run from the Chryssalid, which are going straight for you, but also from the airstrike it's self. XD
Then in XCOM2 Firaxis went maybe a little but overboard with turnlimits, because almost all missions had them, and there was usually not enough time to just creap your way forward. It forced you to take action if you wanted to finish the mission, rather than just creap forward square by square. But then again, that was the intention by Firaxis, because they had found that most people would always creap forward in XCOM1, and the wanted to try and change that a bit. I guess it fits though... since where XCOM1 had been that X-Com was more of an army who responded to alien threats, in XCOM2 you are more of a guerilla force who attacks the aliens instead, where the aliens have to respond to what you do instead. Oh yeah, probably should mention that the canon outcome of XCOM1 is that humans lost the war, so the aliens moved in and took over (think something like that old 80's tv-series "V"), most humans have given in and just do as they are told by the aliens... but then there are olthers, rebels, who are trying to fight back as best as they can. So the turnlimits might make sence due to this guerilla style of a thing that you do. But anyway... one of the biggest critisisms of XCOM2 was the turnlimits, did not take long befor mods came out which incresed the limit, or sometimes even removed them compleatly.
