The internet is now all-pervasive; you’re using it right now, aren’t you? But there is an aspect of it which has been both a curse and a blessing. When cameras were included in every cell phone, suddenly everyone became a photographer.
With the advent of the internet suddenly everyone became a film and theatre critic. Films now tend to show a rating averaged on the number of positive or negative reviews from the ordinary person. These views tend to be constrained to “I loved/hated it because ”
There’s more to critique than being critical
Criticism encompasses so much more than “I loved it”. There’s so much more to think about than whether the story was told at a spanking pace. Students who go to school specifically to look at critiquing visual arts know so much more than the average Joe.
What a critic’s eye can bring
Critics tend to know their market and their environment. For example, New York city cabaret is a great source of information on productions in the Big Apple. Knowing what to expect in the context of what else is happening is a great way of knowing where a piece sits.
A critic will also help point out things you might otherwise miss. Such as the use of filming or dramatic techniques, which enhance your experience, but you don’t necessarily know why.
Critics have seen more than you have. It is their job to compare, so their point of view is informed and nuanced. They know how other influences work and their effect.
But the view of the average Joe can help too, by the way. If you love an action romp and 98% of other people who love action romps thought that this one was good you’re probably going to love it.