Taxation of earnings from labor is on a par with forced labor. Seizing the results of someone's labor is equivalent to seizing hours from him and directing him to carry on various activities.
Philosophical argument, trying to get someone to believe something whether he wants to believe it or not, is not, I have held, a nice way to behave towards someone; also it does not fit the original motivation for studying or entering philosophy. That motivation is puzzlement, curiousity, a desire to understand, not a desire to produce uniformity of belief. Most people do not want to become thought-police. The philosophical goal of explanation rather than proof not only is morally better, it is more in accord with one's philosophical motivation.
Why are philosophers intent on forcing others to believe things? Is that a nice way to behave towards someone?
It is, from another angle, an attack on requiring proof in philosophy. And it's also the case, I guess, that my temperament is to like interesting, new, bold ideas, and to try and generate them.
I think philosophers can do things akin to theoretical scientists, in that, having read about empirical data, they too can think of what hypotheses and theories might account for that data. So there's a continuity between philosophy and science in that way.