That is why it is deceptive.

Now, of course you could say that you should read the article and then you would not be left with the wrong impression... but I think few people read the articles of every headline that they see. Nor should they be expected to, our time is all valuable, we can't all do HN 24/7. Certainly you should always read the article before commenting, but as it stands this headline is deceptive to people who plan on doing neither.

Nor is it reasonable to expect people to not take away impressions from headlines that they don't plan on investigating further. Even if you decided to do that, it would be near impossible to prevent yourself from making unconscious associations.

Headlines should be short, more or less informative, but never deceptive. "Massive PHP bug ...that I almost let through code-review" and "Massive PHP bug" could both be headlines to the same article, but one is deceptive. Unfortunately, it is also the one that is likely to get more hits... Readers who do not particularly find PHP of interest will skip reading either, but the second headline will also (unjustly) form/strengthen a negative association they have with PHP.