It appears that Lincoln was a lot smarter than you, despite your notable hindsight.
He knew that during 1860 the imports of the South were valued at $331 million. The portion of that amount that came from Europe, via New York, would now come to the South through Charleston, Mobile, and New Orleans. There goes the Federal tariff revenue.
The portion of imports into the South from northern sources would now have to compete with European manufacturers. They would not be successful unless the tariffs were repealed.
The northern states imported $31 million in goods. Tariffs on that amount would never pay the US Treasury enough to run the government for a month.
In his inaugural, he said he would collect the tariffs, and he meant what he said. Only problem is that it cost 620,000 lives.
Please provide a link to a source for your alleged information about imports in 1860. You are the guy who thought that tariffs are charged on exports, not imports. Yes, the South exported plenty of cotton but imported almost nothing.