You are entitled to your opinion.
You did mention some points that annoyed you about Seedsman that are valid arguments.
It seems counter productive for a retailer to promote sales to new customers. Yet penalize them on a first purchase.
I get your point.
Perhaps you should write to them about this approach which can be considered as corrective.
There will be one of two outcomes.
A) They don't give a shit about you as a customer.
B) they will answer back with some interesting answers.
I have had this kind of conversation with a lighting company whose name begins with a RED PLANET.
Their response was typical lack of respect to me as a potential customer.
I see this trend happening as some Chinese companies market share grow.
Perhaps Seedsman are at this point as well?
Let them know ( if you write to them).
You will be reporting back to us on the site.
They may chose their words with a little more caution.

EDIT:
Just read this off of the Seedsman site.
Cut & paste : We aim to always give you the honest answer, even when it might not be what you want to hear.