From: Distant Worlds
Actually, with pirates on normal/high settings make for an easy start. Firstly, kind of an abuse, but you can always start ahead of your nearby competition by getting to those independent colonies with much different planet preferential factor. You get the info from pirates about a colony and whether peacefully or not, voila! the planet with a decent amount of completely different alien population is yours to command and help colonize other initially unavailable to you planets.
Don't have to spend all that time on planet research and can concentrate on other areas. The volume and quality of data that one can purchase from pirates is quite impressive and can boost the player into a 'golden age' of fast expansion. Just way too easy. So yes, indeed, the pirate element is more useful at the beginning of the game.
However, different story at a later stage though when the player knows it all about his/her neighbours and the galaxy, and is strong enough to take care of both enemies and 'allies' all by himself/herself. Sure, one can request the pirates to attack an empire without starting a war but without being able to point out a specific target (a base, a ship with a general on it, a research or resort basein a certain system) and considering how weak and predictable the pirates become then there isn't much fun to be had.
Their spawning also becomes quite annoying. Too fast, too small, too close by, the player ends up having to build a mining base in every non-colonized system and cloud with some fuel source in it in order to stop a pirate escort fly brining up that annoying 'red alert' alarm thingie. Pirates are great, the concept is fantastic, always play with pirates on, but think the true potential is yet to be reached. Awaiting shadows with the greatest impatience and hope.
Sorry of I missed and repeated my fellow forum members and excuse my spelling as I am in a big hurry right now.