Of course viruses make computers more vulnerable in the social media era. The Internet started out simple and has grown and involved into what it is today. Viruses have done the same thing over time. They've changed, gotten worse, and targeted certain systems over others to have the largest impact. Given the connectivity between computers worldwide viruses are far more spread able now than they were in the past.
The advent of social media has caused the explosion of usage across the spectrum. Since it takes people using computer and technology to allow viruses to spread, the more people that are using results in more computers being accessed. As more computers are used and accessed, the easier it will be for viruses to spread. Since so many more people are using computers to access social media, the advancement just adds to the vulnerability.
Technologically speaking computer security has greater increased so there's no reason to believe that it would be otherwise. Social media as a platform for viruses isn't even possible since viruses are malicious executable programs; there's nothing to execute on social media and most of the "hacking" is really just weak old brute forcing or phishing scams.
In my opinion, computers are not "technically" more vulnerable to viruses because of the rise of social media sites. Viruses are viruses and are more wide spread now because of so many people using social media, so are more common, but does not make your computer more vulnerable. Whether you use social media all the time, or infrequently you can be infected with malicious viruses without the proper anti-virus protection.
Fully disagree. Vulnerably to computer viruses results from the growing digital crime and consequent personal and corporate information theft. Inventive hackers and other interested parties aim at computer infections with diversified goals - marketing products, clients profiling, criminal intentions and etc. Social media is a convenient access for the interested parties.