Condoms at least send the message that sex can have consequences, and that you'd better think about them first
Close. Condoms send the message that unprotected sex can have consequences.
Some of use want to send another message also, that sex with condoms can have consequences. As I noted in an earlier post, even with perfect and consistent usage, condom failure rates are such that 3% of women who depend on them will become pregnant each year. For typical couples it's 12%.
The failure rates simply would not be tolerable in a less politically correct product, whether you're talking about contraception or disease transmission. To achieve the best performance takes effort, and this performance isn't so good anyway.
I won't claim to speak for the writer of the post our professor was commenting on. But I suspect that this really boils down to what you think about abortion. If it's no big deal to have one once in a while, hey, the odds aren't so bad.
Do what thou wilt. But spare us this nonsense about "safe sex", or even "safer sex". You're sending the wrong message.