Hey.
this is first for me. I've been here for years and never seen anyone complain about the Ivan! That being said, we do appreciate your feedback.
It's quite rare that someone does eventually get both allied & soviet bases (unless they go on an engineering spree, or is playing the Unholy Alliance mode), as such we rarely see this move at all.
Plus, reaching the point where you eventually get an allied/soviet MCV, and build up the army of chrono & ivans would take up a lot of time, and by that point you should have a sizeable army ready to pounce if you get hit with it. There are many counters to this, and I personally don't think that this is a game-breaking move. An example of a game-breaking move would be the engineers. Rushing an engineer and an IFV/Flak and rushing to your opponents base is a bigger game-breaking move than the Ivan (which happens late game, gives you more chances to counter) - which resulted to the "Multi Engineer" option.
However, if more players are vocal about this issue, we might look into having this "patched". Cheers!