I think its pretty common- and I think you're lucky.

I was surprised to see the article say "It happens at least once in the lifetime of every programmer,". I think if you work on greenfield projects your whole career you're likely the one who's creating these 'steaming piles of manure'.

By working on bad legacy projects you learn an awful lot of things about what works and what is a problem to maintain - it will make you a better developer.

The only issue is if you always work on legacy stuff and never get to write greenfield you might get typecast as such. Whether that is a problem of not is up to you. Sounds like you care enough you can change when/if you want to.