Is this a real issue in some countries? I live in the UK and unless you are buying from the High Street there is usually always the option to purchase without Windows included.
A few years ago I went around to buy a laptop without Windows here in Taiwan. 5 places I asked, the general answer was "There isn't a laptop without windows" up to the point where one clerk told me "It's illegal to sell a laptop without windows!" (in all seriousness).
After a few weeks, I've found 1 place that was selling no-OS Lenovos, I got better specs than available for Windows versions, and I'm very happy with it. Still, it was difficult, and as much as I can see, it would be still difficult here in Taiwan, even if more people start to use on-Windows systems, there's just fewer people who demand change like this, because "well, just remove Windows after you bought the computer".... Soon I'll need a new machine and not looking forward to the search. Makes me sad.
It is not so simple. Often you like some hardware and want to buy it but you get no option of getting it with GNU/Linux or at least without paying for Windows which you will then replace with GNU/Linux anyways. You can choose other laptops but often they don't offer what you want, hardware wise.
What if I like the iPad's hardware but want to run Android on it? Is Apple similarly obliged to make that possible? There's a slippery slope here when it comes to forcing manufacturers to offer choices to the consumer, particularly as politics inevitably get involved.
Tablets, phones are expected to be bundled as they are expected to work out of the box, and were designed for that particular OS (the different model of ARM and friends in most cases).
Laptops, PCs are historically not, they are expected to be installed and customized, and were NOT designed for a particular OS, but work as "general purpose computing" (the universality of x86 in most cases).
There's no slippery slope, it's the customers want their general purpose device to be general.
They should obviously be obliged to make it possible. It's sad that Apple isn't treated as harshly as Microsoft by the internet community and regulators.
Both deserve to be criticized for the same unethical practices. Android phone manufacturers may be the worst offenders of all.
If you don't want to pay the windows tax, don't buy the computer. They don't have any obligation to you unbundle hardware and software. Likewise, you have no obligation to buy it. It is a voluntary exchange.
Sure, don't like it don't buy it, but if there's 0% (that's zero) other option, what can you do? That's the case in practice over here in Taiwan that you have to choose between no computer, or one with Windows. That's not really a choice, is it?
Considering that in the EU Microsoft has to provide a choice of alternative browsers (the N edition of windows) I see this as more sane option that addresses the problem closer to the core and I hope that it will be required practice in the whole EU.
After all, a vendor who is confident in the value of their product has nothing to fear in the face of fair competition.