I disagree.
I don't know what I would have done if I had been a Pennsylvania primary voter, but here is my arguement that, regardless of anything else, this was the best outcome, not only for the party, but for the pro-life movement:
1. Specter, while personally bad on abortion, is decent on judges. Bork aside (who is, in my opinion, a little weird, although I don't think I would have voted against him), Specter has been great. We have Thomas because of him, and he has voted for 100% for Bush's judicial picks. And for all practical purposes, judges make the law on abortion right now. Furthermore, Specter won his race with 0 money from the national party and 0 focus from prominent folks etc.
2. Toomey may have won, but he may have lost. There is no way to be sure, but even if he had won, it would have taken lots of national money and focus. As I already pointed out, Specter took 0. In the meantime:
Burr 52%, Bowles 48%
Murkowski 49%, Knowles 46%
Vitter, 51%, Others 49%
Thune, 51%, Dashle 49%
Martinez 49%, Castor 48%
It seems likely, that had we not been able to dump as much money and focus into these races, we may have lost one, or even two of them. If Toomey had then lost, it would have been a disaster. Had he won, we still would have been down a Senator or two that votes our way on abortion. It would have been even worse had he lost.
Also, imagine had we lost the South Dakota or Florida senate race! Both of those would have been major blows. Knocking off Dashle was huge, and I think Castor is one of the worst, terrorist appeasing losers I've ever seen. It would have terrified me to see her in the Senate.
In the end, I think that focusing on other races was more important, and helped not only the party, but the pro-life cause.
First of all, Specter has not been "decent" on judges, he has been pretty bad. He has not lifted one finger to help any conservative judicial nominees, with the sole exception of Justice Thomas, who had the fortune of being nominated a few months before Specter faced Republican primary voters and thus was positioning himself to the right. Don't forget that Specter voted against the judicial nomination of Jeff Sessions, who a few years later became a Republican Senator from Alabama. And as Chairman of the Judiciary Committee, Specter can pretty much block any conservative nominee he see fits, and has "warned" Bush not to nominate "extremists." So had Toomey received that 1% extra he needed to defeat Specter it would have been a huge coup for President Bush's judicial nominees.
And as for your theory that GOP Senate nominees in other states would have been underfinanced had Toomey won the nomination, remember that (i) the NRSCC actually spent quite a bit of money to reelect Specter, first in the primary and then in the general election; and (ii) the NRSCC would have received a hell of a lot more in monetary contributions had it not supported Specter over Toomey in the primary. Toomey would have been able to raise plenty of money without the NRSCC's help, and we would have ended up with the same number of GOP Senators, except with Jon Kyl as Chairman of Judiciary and with a strong conservative in Toomey instead of a RINO in Specter.