As Kiyama said it's because there are too many Spanish speakers who want to practice English and a few native English speakers who want to practice Spanish. I also do what he said. I look for non-native English speakers to practice with, and as Gustav said if you look for a native English speaker who corrects your mistakes you should hire either a tutor or a teacher on this site. That's what I have done when I want someone to correct my pronunciation mistakes.
I'm not quite sure why it is. Maybe because there are a lot of people who speak Spanish around here, and not so many interested on learning it. However, you'll find a lot of people interested on practice English without 'exchanging'. At least that is what I do, search for people interested on talking only English.
I may suggest you practice English without restraining yourself from non-native speakers.
Hi, juan. I have the same feeling with you. Maybe most people are not serious about it. So I just directly find the comunity tutors to practice. Of course, it's not free!