They could make a libre laptop, but the specs would have to be lower. I don't
mind that they compromise on freedom for more modern hardware. It's not
ideal, but there is a set of people who would be unwilling to use any of the
machines supported by libreboot, and I would much rather they use PureOS +
Coreboot - Intel ME than a Macbook Pro or some other atrocity.
However, potential users of Purism's products should know exactly how they
would be compromising their freedom so that they can make an informed
decision, and it is Purism's responsibility to inform them. Otherwise, even
if they learn about some of the freedom issues on our own, they won't know
how many more there are that they don't know about unless they have the
knowledge and time required to investigate.
If, like Technoethical, Purism clearly documented the freedom limitations of
their products, I would have no problem with them, and I bet they would still
be very successful.