Comment by vladich

You make some unsubstantiated claims here. I assure you that it isn't as simple as you claim. And what Postgres does here is (mostly) the right thing, you can't do much better. You simply can't decide what plan you need to use based on the query and its parameters alone, unless you already cached that plan for those parameters (and even in that case you need to watch out for possible dramatic changes in statistics). Prepared statements != cached execution plans.