Common objections to suspension are
weight, complexity, cost. my 2$ (inflation adjusted)
Weight
I have an extra 20lbs of grease on me so I'm honestly not super concerned about the bike weight
. Current ride clocks in about 30lbs, burly build. My backpack is another 5 to 20 (clothes, big lock, picking stuff up on the way home....) so the additional 3-5lbs added from suspension makes little difference in the roughly 250lb total load (bike+rider+bag)
Complexity
After owning suspension for 2.5 decades I have found suspension to be
the most reliable part of the bike 
. flat tires? common. Drivetrain imperfections? of course. Suspension issue? vanishingly seldom.... Service the suspension every year or 2 has been sufficient. I credit a big part of that reliability to Lizard Skins... my previous coil/oil fork went 10yrs with
zero service, felt smoother when used than new (nicely broken in) and had zero slop/leaks etc. 10yrs around 50k miles.
Suspension linkage: I have less experience with this, I owned a Titus Racer-X for 10yrs, about 5k miles total on that, zero linkage issue. Good design+good bearing = reliability.
Cost
no doubt there is a hit here. However in this instance I am willing to make a big invstment in something I love & want to ride to work every dam' day rain shine heat cold!!
