Semipelagian is not pejorative. It no more means semi-heretic than Partial Preterism means partial heretic. Full Preterism is heresy, but Partial Preterist embrace their name, and I believe Semipelagians do also.
I consider Semipelagians brothers. The truth is, so-called Arminianism today is actually not classical Arminianism, but rather Semipelagianism. I realize some don't consider Semipelagians brothers, but they usually also don't consider Arminians brothers either.
Semipelagians affirm the Fall, in that it changed Adam and his descendants forever. They still believe man can exercise faith without being specifically changed by God, but with great difficulty. Aminians and Calvinists believe a forerunning grace and transformation is necessary before man can exercise faith (Calvinists believe this is actual regeneration).
Don't get me wrong, the view is problematic and wrong, but I don't believe it, in and of itself, will keep someone out of heaven. It should be rejected, however.
Hopefully we're not going to apply political correctness to historical terms like Semipelagianism. I, for one, will not comply. That said, some prefer Cassianism, based on its originator John Cassian.
Some articles to take in:
What is semi-Pelagianism? - Got Questions
Semi-Pelagianism - CARM