I am sorry but you're blowing this out of proportion. You're making it sound as if prostitutes were scattered around in every street in Agadir.
Yes some tend to be in some night clubs, but unless you're looking for them when you're out and about, you will not "feel their presence" as you say. I'm not sure which Al Massa Yacoub Street is but as I understand it, nightclubs are where the girls hang out, particularly Papagayo disco at the hotel Tikida Beach. As I've never been in the Papagayo or any other disco I cannot say whether or not this is true. In any case, girls are not all over town or on street corners as in the UK and may only say a few words whilst passing a male tourist.
They are usually just flirting and are not as overt as prostitutes in other countries; they are not allowed into any tourist hotel as the hotel may lose its license. I never saw any prositutes in agadir! You have nothin to worry about!
Just reminded me of an incident a few years ago where some young punk male grabbed my hand and tried it on - not likely matey said I! Morocco is unfortunatelly full of prostitues these days. I saw them in most of the 3 and 4 star hotels I stayed. Where there is alcohol, there are prostitues. If you want to avoid them, than don't go to any hotelbar or club. Surely some mistake on the last post - prostitutes are not allowed into any hotel anywhere in Morocco.
There are bars or clubs attached to some hotels Papagayo nightclub at Tikida, Mabrouk where they will be allowed in but not hotels or bars within hotels. I'm sorry, but unfortunately it is not a mistake. I've stayed in a lot of hotels in Morocco and in all hotels where there was alcohol, there were prostitutes.
