It is very unlikely to meet a person who wanted to work in software testing company from childhood or a person who has graduated from the university to become a software tester. This profession is often an accidental choice.
It happens so that software testing professionals are on their way to reaching some goal and see testing as a footstep, which permits them to get a job in a desired organization, or get into the specialization they really want to be in (more probably software development).
Sometimes they are trying to desert something, most likely a job that has a high level of uncertainty. They may have taken a few studies to obtain the basics of technical skills and are trying to get into a more stable field.
Everything is ok with these reasons to become a software tester. Troubles occur when people are not spare any effort into their work or treat it as though it is just a footstep in their life. People that stay in software testing find it fits their individuality or their natural endowments.
If you decide to do something – do it as well as you can. Even if the job is just a step for you to get more desired position, do it well anyway; and it will serve you tenfold, paying you back in your image, your knowledge, and your satisfaction with the status.
There are a lot of people who really want to build their career as a professional tester, but do not see the approach to perform this. The reason is that it is more of a profession by accident than design, those people that have stepped into the roles may not have planned for a full career path or know the directions that are open to them as they grow.