This seems like an overblown concern. How often are aluminum frames actually failing? How many miles and how many years do you have to put on one before it fails? And how do these figures contrast with steel? And don't forget that steel is more susceptible to rust than aluminum is, so depending on climate and salting conditions the steel might fail first.

My aluminum road bike cost me $600 new and I have four years of daily commuting on it so far. It's still in good condition and I expect to get many more years of riding out of it. At this rate I'm gonna have it for longer than the average car ownership period in the US (which is about 7 years).

The fears are being blown out of proportion.