I'm not entirely sure what kind of loopholes allowing remote work on what would normally be a tourist visa/stay open up, but surely it's preferable for all parties in the "average" case for it to be allowed.
In some ways, a standard tourist is still working for their foreign company, they just are using their allotment of get-paid-for-doing-nothing days. Likewise, a guy who wants to workation for a week still is effectively a tourist. At some point you seem less touristy, which is probably why tourist visas are typically around 90 days.
And US citizens have visa-free travel to Schengen which allows for either tourist or business activities.
See real cases on Google https://www.google.com/search?hl=en&q=b1%20visa%20remote%20w...
Also EU law is separate/different from US immigration law.
In summary, if you can help it, I suggest you don't do any work from the US.
PS: also if you had to deal with USCIS, you'll find there's a lot of things not written on their site, but that are actually important and enforced. Very different for example from Canada, where nearly everything is available online and helping you succeeed in the process. And yes, US immigration many times "doesn't make sense".
But some do.
Be careful.
Total bureaucratic fail, the French company just told me the specific visa was not going to happen, so I cut my stay to fit the tourist limits and went on that visa.