Does anyone besides me think that the writers of Voyager blew it by allowing
the crew to break Warp 10 and then denying that they could somehow take
advantage of it?

Paris said on his first trip that he was "everywhere" and included earth in
his list of places. Granted he came back out of the deal with mutated genes
but The Doctor was able to cure him and the Captain Both in the end.

Now when a person goes past warp ten and is affected the crew knows 3 things
for certain.
1. The Cause
2. The effect
3. The Cure

conclusion:

 A pilot could be sent to earth in the Shuttle with all of the information
needed to fix his mutated genes included in Data and material that Voyager
sends with him.

The pilot could take samples of the new style of Dilithium and all the
technical data needed for Starfleet to duplicate the experiment.

Starfleet could immediately go to work on a plan to bring the Voyager crew
home even if it meant transporting them one at a time and curing them when
they arrive.
or
Starfleet could form a plan to circumvent the effects of WARP 10 + travel.

At any rate, Capt. Janeway should at least try to get a shuttle to The
Federation even if the only thing aboard is Information on the Transwarp
experiment and a sample of the new Dilithium. This is not something she should
just sit on til they get back to Fed Space. It is to important of a discovery.

I think the writers  of Voyager are getting to wrapped up in the Drama aspect
of the show and are failing to remember that Starfleet personelle are made up
of the Best and the Brightest and the most ingenious people around. Someone on
Voyager would have had to come to the same conclusion I listed above and then
acted on it. To think that the crew could make such a major breakthrough and
then simply scuttle the project because of this one problem is an insult. It
is a total let down to all of the veiwers who depend on the crew to find ways
around every problem they come up against in order to survive. To me it seems
that Voyager is just becoming a weekly soap opera\drama instead of the cutting
 edge Science Fiction it was meant to be..

Devious