I actually feel almost the opposite of a lot of people, then. I think that they are very important, but feel like abortions should be handled differently.
In the UK, you have to stay the night in the hospital when you get an abortion. This keeps internal bleeding and infection down, helps with the mental state of the patient, and also keeps it from being used as an 'oops' form of birth control (which I hate to say it, but some people treat it like that.)
I think that Planned Parenthood is essential, as many people don't have the resources for proper gynecological health. I feel like if PP went down, many people wouldn't be able to afford proper pregnancy testing (the sooner you find out you're pregnant, the healthier you can live to help your baby), and many people certainly wouldn't be able to get STD testing (which is an utter epidemic in the US. The more people who get tested, the less likely they are to spread it.)
They also are invaluable when it comes to birth control options. If you can't afford condoms, you certainly can't afford a baby, and they hand them out like candy. (This also helps the STD scene) They also give other birth control options out for pretty much free, which helps greatly. If you're born into poverty, you're likely to have a child very young, which keeps you from getting a good job and going to school. Offering birth control to people without insurance helps them get their lives together and get to a better place.
In total, while I don't really agree with their 'in and out' abortion stance and really like the way it's handled elsewhere, I feel like they are EXTREMELY important.