Ah! I have such products in-house, as well. And, strangely enough, they form a source of unity in our group much as a "common enemy" will cause usually disparate groups to unite in a time of war. They also provide a tremendous source of "opportunity to shine" especially if their code is "open source" like it typically is in SQL Server. Matt Miller hit the nail on the head in his message above where he said...

"There have been times where I've found myself "isolating" them 3rd party products, and starting to cut off its various features to replace them with ones I've written that will actually work without killing a dedicated server."

What an incredible opportunity. Think of it this way... it's impossible to show your worth by correcting a blank piece of paper. Now, that would truly be magic if you could.

Embrace the challenge... start telling managment how you improved the 3rd party software... start getting them used to the idea that you and your team can do better than that and that they'll no longer be held-up at gunpoint by the 3rd party vendor when a change or new feature must be added. After several successes like that, they'll start coming to you and your group for good solutions instead of buying untested, performance challenged 3rd party crap. But, ya gotta trick 'em... you have to "Let them see it your way"... if you try to force them, they'll dig in. And, you have to be really, really careful... that "3rd party POS", as Matt called it, may have been the "brain-child purchase" of that management... you may be dealing with more ego than you know. 😉