Nonsense. What was needed was that they stop shipping most of our grain, meat, manufactured goods, and natural resources to the Soviet Union. The communists weren't willing to do that.
Understandable, given that they were totally reliant on the Soviet Union - let's not forget, a Soviet Union that was unpredictable, ran by a Kremlin full of spoiled old men completely out of touch with reality. I don't think it was an option to simply say "no".
Since we know now that the Soviets had no intentions to invade in 1981, the communists could have reached an agreement with Solidarność, which was a peaceful movement.
Peaceful in what sense? Their strikes were paralysing the country, and their leaders wanted more than the Communists could offer. Power sharing wasn't on offer, nor was it available in 1981 - would Brezhnev have accepted the loss of total Communist control in Poland? More than likely - no.
They didn't intend to invade because the Polish communists had no intention of letting Solidarity share political power. I don't think the Soviet Union was particularly interested in what went on economically as long as Communist rule was intact.
Ten years later they made such an agreement to share power. Solidarnosc was still a peaceful movement. The deterioriation of the economic situation was on-going with the idiotic policies the communists devised. They were the cause of a bad situation.
You can't compare the 1989 agreement with 1981 - the political climate had changed dramatically in Moscow to the point where their leader had openly announced that countries in the Warsaw Pact were free to go their own way. Compare that to 1981, where no-one knew what the Soviet Union was thinking - and Brezhnev had a long history of using force!
As I said - credible alternatives to Martial law? There really isn't any - every time the Communists gave an inch, Solidarity wanted more.