It's worth reading the speech as a whole:

Finally, let's move on to Brexit. As for the negotiations, the situation is pretty clear. Its framework will be set out by the European Council - that is by the guidelines foreseen in the Treaty. Our task will be to protect the interests of the EU as a whole and the interests of each of the 27 member states. And also to stick unconditionally to the Treaty rules and fundamental values. By this I mean, inter alia, the conditions for access to the single market with all four freedoms. There will be no compromises in this regard.

When it comes to the essence of Brexit, it was largely defined in the UK during the referendum campaign. We all remember the promises, which cumulated in the demand to "take back control". Namely the "liberation" from European jurisdiction, a "no" to the freedom of movement or further contributions to the EU budget. This approach has definitive consequences, both for the position of the UK government and for the whole process of negotiations. Regardless of magic spells, this means a de facto will to radically loosen relations with the EU, something that goes by the name of "hard Brexit".

This scenario will in the first instance be painful for Britons. In fact, the words uttered by one of the leading campaigners for Brexit and proponents of the "cake philosophy" was pure illusion: that one can have the EU cake and eat it too. To all who believe in it, I propose a simple experiment. Buy a cake, eat it, and see if it is still there on the plate.

The brutal truth is that Brexit will be a loss for all of us. There will be no cakes on the table. For anyone. There will be only salt and vinegar. If you ask me if there is any alternative to this bad scenario, I would like to tell you that yes, there is. And I think it is useless to speculate about "soft Brexit" because of all the reasons I've mentioned. These would be purely theoretical speculations. In my opinion, the only real alternative to a "hard Brexit" is "no Brexit". Even if today hardly anyone believes in such a possibility. We will conduct the negotiations in good faith, defend the interests of the EU 27, minimise the costs and seek the best possible deal for all. But as I have said before, I am afraid that no such outcome exists that will benefit either side. Of course it is and can only be for the UK to assess the outcome of the negotiations and determine if Brexit is really in their interest.

He's clear that he understands the UK position to be no ECJ jurisdiction, no budgetary contribution and no (or at least, less) freedom of movement. So his position is that the UK is not seeking a soft Brexit deal, and therefore won't get one.

I think you're right to suggest that if the British position did include freedom of movement, acceptance of EU law and contribution to the EU budget, a soft Brexit deal would be possible. But the British government has explicitly ruled out all three of these, the EU isn't interested in persuading them otherwise, and Tusk has drawn the natural conclusion.

It was one of those things that once you've thought of it, you can't unthink it! I did manage to restrain myself from actually saying it in the meeting until my closing remarks.