Wikipedia does not contain the truth. ("The threshold for inclusion in Wikipedia is verifiability, not truth.") I disagree with many of the things that are stated in Wikipedia, but I do not feel compelled — much less entitled — to change them.
Articles in Wikipedia, at their best, reflect the general state of human knowledge, or in other words, what most qualified people are saying these days.
I reserve the right to believe that most people are wrong about some things. But I do not have the right to make my opinion prevail in Wikipedia.
Wikipedia is an encyclopedia. The primary job of Wikipedians is to write it. Everything else is secondary.
The very existence of Wikipedia is a massive proof that there are more people in the world wanting to build than to tear down. Were that not true, vandals would have overwhelmed and destroyed us years ago.
The best way to continue as a writing Wikipedian for many years is to be, as the Buddha recommends, "indifferent to both praise and blame." Indifference to praise is a hard task for mere humans, but millions of potential anonymous readers demand it of you…. And remember this: you are allowed to take your work seriously here, and think highly of your own efforts; but be advised, don't talk about it.
A common insult hurled at dedicated Wikipedia editors is that they "have no life." If you write extensively in an out-of-the-way area, you may well become the most widely read writer in the world on your topic. There are worse ways of "having no life", such as abusing the few actually useful people on the internet, but those who deliver such insults are invariably tone-deaf to irony.