Here's what consumers have asked with answers from Putlocker.is staff and previous consumers.
You have to understand that the people at putlocker would have to put in subtitles manually and since they upload so many movies every day it would be very difficult for them to do so. More so in different languages they cannot afford people who know different languages to do subtitles since those people aren't widely available and have better jobs as translators in real life. They are probably already understaffed and have their own families to take care of. They simply do not have to time to put them in.