Torro Rosso is a team that's meant to be a Red Bull B-team and no more, so Red Bull doesn't inject much effort into STR, so they are unable to prosper. I think Buemi and Alguersuari are doing well considering that they have the slowest midfield car, Williams seem to have sorted themselves out and are now back where they were in 2010, ahead of Force India, so that leaves STR at the back, ahead of the Lotii etc. They don't deserve to be treated as average, and there is NOTHING that says that Daniel will be able to do better than either of them. Jamie is 20, he's still very young and gets better race after race, Buemi is also doing better than ever.
And about Narain, the guy hasn't been in F1 since 2005, and is now having to re-learn the tracks and learn new ones. He hasn't been at Valencia, ever, for example. And in qualifying, he has still managed to often come within half a second or less to Liuzzi, and even he has been able to outqualify a Virgin. And another thing, Narain hasn't crashed this season, at all, which is good considering the fact that that HRT has relatively low downforce and so is quite unstable at times. Handing the keys to a rookie with relatively little experience in F1, and none in the car that's unstable to drive is a gamble, one that HRT shouldn't take. They are better off with experience to help develop the team and move forward, they don't really need pay drivers as much anymore, as their budget is bigger than before, and they are on stable ground this year, unlike 2010. And through Narain, they get both experience and money.