You could be right if it is Huawei. But ZTE is SOE and it carries the task of geostrategic nature from the state.The issue at least i believe is ZTE try to make $$ not about politics or geo balance while fully aware of US sanctions on IRAN .The issue make worse when ZTE parts sold to Iran contains US made part then try to cover up in lawsuits . It made a risk decision that hurt them more than what ever the profit they gain from Iran
Another example is CNPC (中石油) investing in Iran. China buys lots of Iranian oil, even rejecting Saudi's offer of cheaper oil, that is strategic decision. CNPC is ZTE in this case. To bypass or minimize effect of US sanction, Kunlun bank was setup to handle the finacial matters between China and Iran. Kunlun bank has been sanctioned by the US, but Kunlun does not care because its sole purpose is serving Iran and other US targetted countries, it has zero business in US "world".
Recently, reuters reported "". Total is the franch company who gained 50.1% control stake in a gas project in Iran in 2017. Now after Trump reimposing sanction on Iran, Total's commitment to the project is crumbling, while CNPC (owning 30%) is prepared to take over that 50.1% from Total. That is the power and purpose of SOE.