No it's an entirely reasonable and obvious point of view to expect a mainstream company to sell lights that are fit for purpose and legal to use.
The fact it is reasonable and obvious does not, unfortunately, mean it is correct.
It is simple fact that the law requires (when cycling after dark) that you have a front light and a rear light which both meet the relevant British standard (BS 6102 part 3) or an equivalent European standard.
It is also a fact that hardly any of the lights sold in the UK actually meet that standard. I'm pretty sure that none of the Cateye lights do.
They can still be sold (without any disclaimer), because most of them are legal to use as a second light. The only requirements of optional additional lights on pedal cycles are that they are the right colour (white to the front, red to the rear).
But there is still an obligation when they are in use to not dazzle other road users.
If there was any legal grey area I'd have also expected to see a prominent disclaimer on the website advising recommended use
There isn't any.
The lengths some try and go to to be contrary on this forum never fails to astound.
It isn't "being contrary", it is just stating the facts.