The resistor in the emitter circuit provides negative feedback.

Yes - and that.

Its the DC component of that nfb that stabilises the transistor.

 

The resistor in the emitter circuit provides negative feedback.

Yes, but that was specifically not a part of this particular project's learning objectives. I wanted students to first deal with open-loop design problems so that they could better appreciate the effects of adding feedback later.

 

Not if you want to make any money or stay in business. Now, if you are doing a project that has weight/size/cost budgets that will allow you to take this approach profitably, then the marginal savings in design cost (since you aren't spending time deciding whether to add a heat sink) may be worthwhile. But what size heat sink?

But if you are designing a product that has tight budgets in one or more areas and especially if you are designing something for a high-volume market that has competition, then you are being irresponsible to put heat sinks where they aren't needed -- to the degree that designing products that are not competitive in the market place is "irresponsible".

I agree. That's a comprehensive approach. I looked at it from a narrow point of view.