Shouldn't interfere with results? I completely disagree.
Sheik manages to take Marth's double jump with a f-air at low percents. His up-b won't make it back to the edge, so he aims for the platform. Call this point A. Scenario 1: the platform does not save him - he loses the stock. Scenario 2: the platform saves him - Sheik is obviously prepared for this, so she.... does what? Sheik can not guarantee taking Marth's stock anymore, no matter what she does. From point A, what is the difference between scenario 1 and scenario 2? Whether the platform decides to appear in that spot at that point in time, which is completely random.
Someone else brought up the scenario of two characters with poor recoveries trading blows and flying to opposite blast zones. Maybe they both use their double jump and clash aerials, so they're off-stage with only their up-b. Both characters can make it to where the platform rises, but no further. It saves one, but not the other.
Even in high percent situations, if the recoverer can only make it to the platform, and the platform saves him, all he has to do is hold shield. The platform rises faster than can be reacted to, so the edgeguarder must attack at the apex of the platform's path, as hoping to land a hit while it is rising cannot be done consistently. The recoverer holds shield and puts his shield up before the edgeguarder connects with an aerial, and suffers at worst an edge slip. At this point, the stock is no longer guaranteed by any means.
Look at it objectively. Why does it matter that occurrences of randomness are restricted to two locations? In the end, this randomness still has the ability to affect a match drastically. Is there truly an objective reason as to why the platforms are okay, while Pictochat's drawings are not, or does it just feel better to be ****ed with by the platforms?
On the other hand, is it so unrealistic to believe that one day players will be able to expect all drawings at all times and plan around it? There are a finite number of drawings, and a rough timing guideline. You say it's impractical, but that's not obvious to me.