Some web site do block access based on browser type, so don't jump to conclusion that it was written by fools.

Firstly, the error message alone is enough to verify that the implementation is poor and that the implementor doesn't understand the libraries they've used, nor how to perform validation. Both are required in the construction of a simple server-side web-application.

Secondly, blocking access based on browser type may be acceptable for a group of in-house consumers with SOEs interacting through some corporate portal... however, it's completely unacceptable for the public internet.

-David

Update: Actually, recent court decisions about website usability for the visually impaired have probably set the precedent (at least in the USA) that functional discrimination based on browser type is illegal.

I don't really like where that argument concludes, but it's another example of laws catching up with Internet best practices.