I think the wide-angle lens view is that steel is durable, but heavier than other materials and can of course rust. Aluminum is lighter but has fatigue issues with LONG use. Carbon fiber is fine but if you crash or drop it, the material will break. Ti is lighter than steel, should not fatigue or rust, and if made properly should last a long time. Of course some metals can become brittle and if not made properly it can break.

So each material has something really good to offer and (of course) some drawbacks. Nothing is perfect.

That said, when I got my "forever" bike I did choose Ti.