Oh, I understand that.
The thing is, that I believe those same people could use their skills for other things that would actually be for the benefit of the "Librem Phone" development, while still being a good marketing device.

Let's face it, the Librem 5 will only be attractive for geeks who for some reason or another want a slow FLOSS GNU Linux phone with basically no apps rather than one of a bunch of fast pseudo-open Android phones with plenty of apps.
You don't get this kind of people by letting them select the default ringtone, but by showing that you are able to tackle the technical challanges that come with such a project.

I'm not sure how to feel about the Librem 5.
Making a lot of buzz is clearly the core competence of Purism (in that regard they are a bit like Apple). Yet they somehow managed to pull off the Librem 15 and 13 laptops. So amongst all that noise must be some technical knowledge and I think one shouldn't mistake their abundance of buzz for a lack of technical skill.
On the other hand, so far they failed to deliver the Purism 11 deatachable, which has been on their agenda for quite some time. Maybe there's a pattern here that they fail to deliver more compact devices which tend to be harder to design while being able to deliver comparatively more simple laptop designs. In that case I'd agree with you that they won't be able to deliver the Librem 5, but so far I'm willing to give them the benefit of the doubt.