When one analyses issues of homophobia/racism/etc. they have to look it through an emotional lense because they are social constructs and social constructs are based on the fact that humans are a) social b) emotional. While there is empirical data on these sorts of things you have to take into account how emotions play in affairs because... we are emotional beings and not robots, and we can't just scoff it off by saying "I can do x they should too" because people are different and we have to hold those differences into account when we look at issues like this.
Bit of a side track here, but I think it's worth talking about and it's related to the main topic.
I agree that people will likely interpret such things in different ways based on their experiences and personality. The question, then, should be "how considerate can we reasonably expect people to be in a social setting?" That's a difficult question to answer. I don't have a useful answer; you'll have to decide what's reasonable for yourself. Keep in mind, though, that a lot of the problem is going to be ignorance, not malice, especially if the contentious statement is something most people wouldn't understand to be contentious.
Also, I think some kinds of speech should not need to take the feelings of others into account. Personal expression, for example. Your right to freely express yourself should not be burdened by any restrictions (outside of a few exceptions, such as outright lies or calls to violence), including what other people might think of your beliefs. If there's something wrong with someone's expressed beliefs or arguments, the correct response should be a rational rebuttal, not an attempt to censor expression on grounds that it's hurtful.
I also feel private conversations should be somewhat protected. US law describes what is known as a "reasonable expectation of privacy," which is used as a test to determine whether certain discussions or actions are protected under the fourth amendment. This is a very specific legal concept, but the idea is something I think we can usefully generalize to a lot of situations. If someone makes a statement that they can reasonably believe to be private but that statement is somehow leaked, I don't think it's fair to treat that statement the same way we treat something expressed publicly. Many things said in private are not fully thought out or even made seriously and I don't think it's fair to judge people on those kinds of statements. If it's something you take offense to, keep in mind that it may have been an intermediate position someone held as their understanding of a topic was evolving or something taken out of context.
This is a difficult topic. I think some folks are a bit too quick to dole out judgment in some of these cases. Most people aren't trying to be mean. On the other hand, there certainly are some people who act mean just because they enjoy the reaction other people give them. Those people are jerks and I'm not defending that kind of malicious behavior.