At the same time the colleges and universities were churning out Java trained graduates that you could scoop up for a dime a dozen.
Java devs were cheap and as long as you believed that all you had to do was throw more bodies at the problem then you were in a sweet spot.
Having said that the company is still going strong and doing very well thank you.
What it comes down to, and I suspect that this is especially true for large companies, is that if you need a lot of programmers then there are far more Java candidates available that you can hire. They are cheap and replaceable.
Any other language, even hot languages like Python and Ruby, are harder to recruit in numbers and consequently more expensive and harder to replace.
Not sure where PHP figures in all this :)
But Amazon, eBay and Citysearch are examples of companies that started with Perl and then made such transitions to Java/C++. (With an exact mix and history that varies. For instance I believe that Amazon still uses all three, while eBay went from Perl to C++ to Java in complete rewrites.)
Do you know of any small companies that grew to a point and said "Well, we've got a hiring bottleneck since there are much fewer good Python devs out there. So let's migrate to Java which will then pay dividends over the years since the cost of maintenance will be low."