What options do Canadians have? Deal with the wildly capricious economic policies of the US president, or go seeking other, more stable opportunities elsewhere? Almost all countertariffs we have in place are targeted as opposed to the sweeping tariffs Trump is implementing.
They could seek other opportunities elsewhere without adding tariff themselves: continue to import from the US and other countries like before. They may indeed export less to the US due to reduced demand from the US, but reciprocating the tariff won't help with that.