My guess is "consumer rights". I am not familiar with any legal details, but particularly in the EU there seem to be so many obligations when you sell to consumers, which either don't apply at all or can be negotiated in business-to-business relationships: Compulsory warranty, liability, localized manuals, WEEE electronic waste collection, etc. Life becomes easier when you can credibly show that you only cater to business customers.
This is my guess too. Documentation and marketing collateral becomes legally binding offers and promises. A consumer can destroy the frontend of a VNA in ten seconds, then turn around and demand it be fixed or replaced under warranty, pointing to consumer protection laws. A consumer by their very nature is not supposed to be what in the U.S. is called "an expert in the field", no pressing of buttons or plugging things in is supposed to destroy $30k worth of equipment without warning. Consumers have rights to third-party repair, legal recourse if a firmware update bricks a device, and so on. Lots and lots of legal protections that simply don't exist in B2B, where unless it's stipulated in the purchase agreement it doesn't exist. Industrial customers are expected to be "experts in the field" and able to do their own evaluations and consider their purchases. Of course, a voltmeter might be more durable, but it's still requires being prepared to handle consumer protection laws, interact with government agencies to resolve complaints, etc.
In the U.S. whether a sale falls under an industrial or consumer rubric depends on the item sold. In the EU it depends on the buying legal entity, whether it's a private individual specifically. I think the latter is a problem, as it effectively risks preventing private individuals from buying industrial equipment. (And T&M is categorized as industrial in the U.S.) U.S. law also excludes statutory consumer protections from parts and kits, but the EU doesn't and I would fear even more than T&M that if I lived in the EU eventually component distributors would stop wanting to do business with me as well.