If they want their opinion to be taken seriously, they should setup democratic vote among employees to collect votes anonymously about the issue at hand.
Proceeding otherwise is simply trying to convince colleagues but also removes the possibility for other employees to have their voices heard anonymously.
Fortunately, in fact, plenty of organized people have been taken seriously, and have effected change, through other means.
By possibly bypassing the majority's opinion. Also called authoritarianism. Putting pressure in a non-democratic way is silencing people's opinion and similar to censorship.