What exactly is worrying you about the number of collision checks? Are you not hitting 60 FPS and the profiler is indicating that most of the CPU time is spent there?
If you look at the per-tick estimate, it's only making about 20 collision checks per tick. That is very few. A single collision check is very, very fast, practically negligible performance impact. It's a simple rectangle bounds check. You can have thousands of collision checks and have almost no performance impact. Poly checks are the slower ones, and the debugger shows you're getting about one poly check per tick per object, which again is almost nothing.
The platform behavior does make a lot of collision checks in general though. Take a look at the 'Bouncing balls' template that comes with Construct 2. It shows an almost identical effect to the one in your example, except it's based on the Bullet behavior, which users far fewer collision checks.