I disagree, I think the Thrush has its place as a fast-acting LRM. Great when trying to catch fleeing ships compared to the slower, higher dps LRMs. Its speed also lets it double as a close range extra burst of HE damage against an overloaded target if you aim it well (you do generally have to aim them if you're close enough to see the target, as yes, they're not very maneuverable).
Also, you're also comparing it to a short range limited-ammo shieldbreaker missile, the Thrush is better compared to the Pilum, as it's a regenerating-ammo long range suppression HE missile.
Good missile, suggest keeping it as it is.