Plus they were being flown on remote control without an actual human pilot inside, so the suits weren't really being flown with self preservation in mind. They were drone tanks for all intents and purposes. Target, fire and attack were their primary mission goals, avoiding being hit wasn't really a huge factor.
Plus, the Marks 3-7 were about as strong as these other suits really, they took a lot of damage and the only thing that kept them flying (besides plot) was that Tony was inside doing what he could to keep them going, diverting power, boosting shields or whatever and other stuff, why would he say things like that if JARVIS could do it all automatically, JARVIS can't.
Plus it was clear that the heat they generated was extremely extremely hot and more than enough to cut through an empty suit or even a worn suit without much effort. Hot knife through butter.
Although one thing that I am rather... well curious about... if all or most of his other suits could be deployed and worn by them simply opening around him, without needing the whole process we saw in the first 3 Iron Man appearances, what was the real point of the Mark 42? Sure each piece could be controlled and deployed with gestures and thought and could be completely independent, but we saw other suits doing similar things. Plus they just opened up around him like his Avengers suit and later Rhodey's suit and all the others.
I mean the 42 I suppose was just yet another prototype he was playing with, but even so didn't really seem super necessary once he figured out some of the key things that made his other suits more of a chore to wear.
No longer needing to use his own arc reactor for power - they all presumably had their own now. They were able to be worn without the helper arms. And they could now be entirely piloted by JARVIS so if he needed another suit, he just had to call for it.
I still think he had more than one armory than the wine cellar suits we saw. I'll bet there's another armory in NYC - even if it's only variations of the Mark 7/8.