In other words Self-Selecting polls, ie polls where people choose to answer them rather then are randomly polled, are always biased and don't actually reflect the true opinions of the whole, but only those who are very interested in the topics being polled on. They are great "for fun" but Bioware should not take the results seriously and if they are interested in polling their user base they should conduct a truly random selected poll.
I disagree. When you are working with a closed aperture of poll respondents (such as subscribers only) and it is that specific set of respondents you want to gather data from, any bias from voluntary poll response is marginal. Why? Because there is in fact randomness in the samples in an interest group, yet no fly randomness that tends to bias.
In addition, the OP inoculated this poll quite well from selection bias by allowing up to 5 responses. This largely disarms collective efforts to drive a specific bias.
On the other hand... if this poll were open to everyone on the planet... then it would be harshly biased by self-selection bias. A good example of self-selection bias among gamers is the survey that selected EA as the worlds worst company. A very small fraction of total available survey population, with a special interest in smearing a company, was able to in fact drive a survey bias.