Is front-suspension a false-economy for cheaper bikes? I'm a 30 year old male looking to purchase my first non-department store bike. I haven't biked in more than a couple years.

My use-case is 90% asphalt (inner-city, occasional low-speed highway) and ~10% trail. Trails would typically be flat, straight, with few serious bumps. The bike could see very occasional heavier use.

I've seen several arguments against the use of front suspension forks on Hybrid bikes in the $0-$500 range, with arguments levied against them including:


They lack lock-out at this price point, making city/uphill travel more difficult.
They add weight to the frame.
They limit speed.
They require maintenance.
Its another moving part that could fail.
They're ultimately unnecessary for this use-case.


Of these arguments, speed is probably the one that I can most easily disregard, as I am not looking for high top-end speed. On the other hand, if a suspension fork at worst won't hinder me, I would see no real point in avoiding purchasing one.
Benefits of suspension forks (city/gravel road use):


Remove chatter from bumpy roads
Take the jar out of major bumps
Better traction


Drawbacks of suspension forks: 


Entire bike is heavier, leading to a less agile bike.  A bike with suspension (all else being equal) will hit more holes and hit them harder.  It will also climb like a pig and accelerate poorly.  
You will learn much better technique when riding without suspension.  Things like hoping curbs and avoiding potholes become more important but also easier.  The bike will give you clearer feedback.  
Make the entire bike feel spongy and sap your energy.  
Suspension dives under braking, making the bike perform as if it had a steeper head tube.  This causes more twitchy handling at a poor time.  
On cheaper models, behaves more like a pogo stick that bounces.  This may actually make bumps more extreme.  
May not be adjusted to your weight.  If you are lighter, it will act very much like a rigid fork.  If you are heavier, it will be permanently compressed and not doing you any favours.  
Service - City bikes can get many hours on them between service.  Some forks require servicing every 100 hours of riding.  The cheap forks that will come on a cheaper bike may not require this level of service (many are not serviceable) but still something to consider.  
Simplicity.  


If you have a suspension fork you risk: 


Paying more for your entire bike
Trading better components for cheaper ones to offset the suspension cost
Having a substantially heavier bike


Other options: 


Putting wider tires on a bike, or buying a bike that can accommodate wider tires is in my opinion always a better option (for a city bike).  This allows you to adapt your bike to different conditions and change it cheaply when you want to.  It is possible to remove a suspension fork but that is difficult/expensive.  See this question I asked about swapping out a suspension fork.