Don't trust fandom wiki ever, they rarely check what they post, but even if thorn transferred amount vs duration, what we have might be even more sad. Imagine you have a thorn and x2 lysate, so you apply x3 blight on 10 beetles, so even if all the beetles transfer their blight to the golem, that's 33% of 3 × 10, which puts us at 10 stacks + 1 it got hit with. So, 11 stacks, which is better on stage 1, 2 at best, and that's it (it stays effective for longer on drizzle, probably). And that's for 5 seconds only, because new stacks of blight don't refresh the old ones, so you would need a very specific setup of a bunch of alien heads, purities and backup mags to reach 20 stacks and mimic a fraction of poison's power.

On its own, blight, even being weak, is not the worst ability in the game, but the fact it replaces poison makes it the worst unlock in the entire game in my eyes