To start off with, I disagree with focusing on Day 1 patches as a problem. I believe that the true problem is when a game is released in an unacceptably broken way or makes it outright unplayable. I believe we can all unite together against that issue.

Furthermore, I think that the main thing responsible for it is the pre-ordering phenomenon. Back when we actually bought games at brick and mortar stores, scarcity was an actual issue. If we didn't pre-order to reserve a copy, they might run out before we show up to buy it and so we would have to wait for them to receive the next shipment so that we can buy the game.

With the advent of the digital age, where the vast majority of us download our games instead of buying a disc, scarcity is no longer an issue. However, publishers have resorted to a variety of tactics to keep pre-orders alive. We mainly experience this in the form of pre-order bonuses, Day 1 DLC, and a gaming industry that, for all intents and purposes, blackmails the game reviewing industry in order to create false hype for their game.

You correctly identified the issue at hand as greed. The larger the proportion of pre-orders is to non-preorders, the better estimate a publisher can make about how profitable the game will be for them. That is immensely useful to them and their ability to profit, and that is why they have an incentive to keep us pre-ordering their games.

A cancerous problem that arises from the pre-order culture is the possibility of gamers to get ripped off with awful games that we have paid for before we realize that it is awful. Anyways, now I will move on to why I 100% support day 1 patches.

To start off with, it does not matter if you, or me, or anyone else loves or hates day 1 patches. They are a reality of a digital release model and unless digital releases go away for some reason (they won't) then we will have day 1 patches from now on. But this is a good thing, PROVIDED THAT IT IS NOT ACCOMPANIED BY A BROKEN GAME. But let's discuss WHY it is a good thing.

For starters, there is a time span between the deadline for code being finalized an d the actual release. In this time span, new issues can be identified, new fixes for them can be prepared, additional optimizations for the code can be prepared, and more things that didn't occur to me in the short time that I wrote this. But perhaps an even more important issue, is that there are billions of possible combinations for Computers due to all the millions of different parts that we could choose to build our PC out of. There is no possible way for a game developer to account for all of those combinations, and so there will always be opportunities for them to increase the game's performance on a wider variety of computers.