Is this another RSV thread? If so then I can understand the sentiment, as their actions in that case APPEAR to have been unethical.
If not, then what is wrong with EVO taking a short position in a share?
Shorters bring greater efficiency to a market - what is wrong with that? Look to markets where you can't short a stock... you will find clusters of companies with crazy market caps, e.g. some companies on OFEX.
If EVO (or anybody) takes a short position that you don't agree with, then why not buy all the shares they short-sell and make them pay for it if the price rises, rather than moaning about their success on bulletin boards?