It's more along the line of Towers Watson being done away with by a free website, it's just a typical corporate minded response. Compare it to Encyclopedia Britannica which for years owned the top spot for knowledge, being made irrelevant by Wikipedia.
But there is nothing stopping another survey being made with rephrased questions and a different answering scale which seems to be the problem that TW have with this all.
TW don't own the rights to the english language or a rating scale of 1 to 6..
And, even though we would all be inconvenienced, I'm sure all aviation employees would understand and be more then happy to participate again in a community produced and driven engagement survey.. in fact we might get even more responses in backlash to TW's actions.
And at the end of the day, what is stopping this from being a regular bi-annual effort for the benefit of the whole industry. Collaborate with the companies involved and they might be more then willing to use the results as their own benchmarks of their own performance and potentially save themselves millions in consultants fees in the process.