OK, all this "we can leave with no deal and trade with India and be fine" is bollocks.
Hopefully, we will leave with deals in place. Some kind of transition arrangement would be very sensible, but not popular with hard line brexiteers.
But IF we walk with no deal, what happens in the short term?
What happens in April 2019?
What if my employers were due to send me to the Hague for a meeting/conference? Will I be able to get off that plane in April? Will that plane even be able to land in Schipol?
What about the delivery of tinned tomatoes due to arrive at my local supermarket? Will the lorry they are on be able to enter the UK? Will the haulagers know what the policy is, will they know where they are allowed to go and what they can deliver?
What about a UK tap manufacturer, that imports a certain seal from Germany? Will they be able to meet their orders? If their consignment cannot enter the UK, will they get a refund on what they have paid? It is, after all, not the supplier's fault.
What will happen to the exports of that business? They can't ship to the EU anymore. They can't ship abroad until new deals are arranged. Will the government communicate clearly and promptly with businesses to let them know who the can and can't export to? While it gets sorted out, will the company have enough capital to keep paying the wages of their staff? What if they are a SME? Will there be government assistance to help them?
Scale that up to thousands of travellers, travelling for work and leisure between the UK and the EU. Include many more people transferring flights within the UK, or within the EU.
Scale it up to include many more food imports (27% of our food comes from the EU).
Scale it up to include thousands of businesses; manufacturers who can no longer import/export their products and components; companies within the service industry who suddenly lose all their EU custom.
Yeah, you say we can replace all trade with India and the US, grow and tin our own tomatoes etc. But even being ridiculously optimistic about that and assuming we get some awesome fast deals, do you have any idea of the logistics involved in transferring all our trade to those countries? These things normally evolve and shift over time, changes are phased in. You can't flick a switch and suddenly replace all EU imports with ones from elsewhere, nor can you double UK food production overnight just by saying "lets double UK food production".
While you're waiting for all these amazing new deals to happen, businesses are folding, investors are losing confidence, people are losing their jobs, supermarket shelves are emptying, travellers are stranded, planes are stuck on runways, and the world is watching us look like twats.
Leaving without a deal would be very bad for the EU, it would also be very inconvenient to the rest of the world, too (I am sure they will be greatful) but I cannot over-emphasise how disastrous it would be for the UK. If you cannot understand that, and refuse to even acknowledge the questions in my post (a mere sample of the uncertainty that would ensue) then you are either irredeemably stupid, or you are doing a very good impression of being so.