Wrong Title and not enough respect to the title Engineer
Two points here
First is that the term 'Engineer' is hopelessly mis-used.
Too many people call themselves engineers when they have no right to do so.
Those people at Microsoft don't help matters by creating those pesky MCSE courses either.
I'm sorry but that particular qualification means, at best, you can call yourself a technician. Not an engineer.
To be an engineer you need to have, at least, a bachelors degree in an suitable subject, an appropriate level of experience and pass the entry requirements for one of the accredited institutions such as the IMechE.
IIRC they actually have recently increased the requirements from Bachelors degree to Masters for all new entrants.
So anything that helps bring back the prestige to a title that, in terms of study, is equivalent to that of a Doctor or Barrister.
Second point is that getting the Queen to head up the prize is absolutely ridiculous, what connection has she ever had to engineering other than possibly opening a few factories?
A more appropriate choice would have been Sir Joseph Whitworth who pioneered the idea of standards in engineering. Specifically with regards to screw threads. This development meant that items could be designed in different factories and assembled in remote locations safe in the knowledge that it would all fit together.
Something that is seen today in every industry. Think back to the RFCs or the development of standard PC architecture in recent years.
Arguably Joseph Whitworth was the giant upon whose shoulders Brunel rode because the rapid expansion of the railways, bridges and iron clad ships would not have been possible without the work performed by Whitworth.