What is your opinion on companies that offer high salaries to fresh graduates from tier-3 colleges with low skills?

First of all, colleges don’t have low skills; I assume you mean graduates with low skills. It’s a rare company that will offer a job to anyone they don’t think can do the job, so they’re going into the hiring process with eyes wide open. There could be many reasons why they’re not getting applications from academically top-of-the-line students (or rejections of their job offers from them) - such as location, company reputation, type of job and salaries that are far lower than those grads can get elsewhere.