Elections are not polls. Elections are more complex, driven by which party has a greater chance of making an impact. Smaller parties tend to get fewer votes not because their positions are unpopular, but because their capacity to make change is smaller. Furthermore, Marxists are, in general, against electoralism. This is fundamental to Marxism.

The sample size in the Czech poll was large enough for a coherent view of general opinions. Most professional polls are between 400 and 1000 samples:

sample size of 400 will give you a confidence interval of +/-5% 19 times out of 20 (95%)

A sample size of 1000 will give you a confidence interval of +/-3% 19 times out of 20 (95%)

This is basic statistics. If you aren't familiar enough with polling to understand degrees of confidence, then you aren't in a position to argue against the validity of polling based on sample size.

Finally, if you check the up/downvote ratios, it seems pretty much nobody is agreeing with you and everyone is agreeing with me. Your comments are having the opposite effect, they are legitimizing me. People on the fence seem to be siding with me.