> ... it will just make weapon makers start designing high-speed missiles with the radar signature of an airliner lol.
Well, the problem with that is that airliners are (relatively speaking) slow as fuck. A "high-speed missile" with the radar cross section of an airliner would be mind-meltingly obvious as a threat even to automated defense robots.
There are cruise missiles powered by ramjets that go significantly supersonic, but for the most part ballistic missiles are easier to use, longer range, and harder to intercept. The prospect of anti-air systems effective enough to pose ballistic missiles trouble in a "near-peer" non-nuclear conflict is recent. Both maneuvering-capable ramjet/scramjet cruise missiles and (the significantly easier) maneuverable hypersonic re-entry vehicles that launch ballistically, are the subject of recently fielded early models, active development & active testing because of that prospect.
Airliners aren't slow by cruise missiles standards: supersonic cruise missiles are few and far between, and most cruise missiles in fact fly roughly at the speed of an airliner (between 800 and 1000km/h).
You're the second person to talk about cruise missiles in this subthread.
The comment I replied to (and quoted in my reply) talked specifically about "high-speed missiles". Nearly all cruise missiles are most emphatically NOT that sort of missile.
Well, the problem with that is that airliners are (relatively speaking) slow as fuck. A "high-speed missile" with the radar cross section of an airliner would be mind-meltingly obvious as a threat even to automated defense robots.