I don't think it's that using Perl6 day to day is going to be more complicated, just that understanding the resultant crap is going to make the life of maintainers even more horrendous that it is now.
For example, the statement above is not too helpful. I mean, what aspects of Perl 6 do they have issues with? The complexity of the language? We've had this debate over and over - the changes to the language are designed to make it easier, purer and more simple to program Perl. But that's not the point is it?
You see if someone had said "I'm worried about the complexity the changes in Perl 6 are introducing and it's knock on effects on software maintenance" then they'd be something to answer. But that's not the way FUD works. You make a statement that is one point but in it you slip in a passing blow at some other aspect. In this case rather than just conceding the point that it possibly might be easier day to day to use Perl 6, you transfer the problem to that of maintenance, and label the output (i.e. what people were programming what was your original point that you just conceded) as crap sidestepping the issue.
Let's compare that with Java:
Java is exactly like interpreted C++.
And what I mean by this sentence ?
C++ is designed to be a compiled language not for run time interpretation like perl/python
When Java developers ripped C++ I think they forgot about that
Now you know why Java is so bloated....
That's from here of course, where else. Different language, same M.O. Notice how the poster makes two valid points that Java is like C++ and that C++ isn't designed to be interpreted and draws the conclusion that Java therefore isn't any good at interpretation, neatly skipping all the important fact that quite a few of the differences in C++ and Java tend towards run time interpretation (er, reflection, bounds checking, etc) Now I'm not saying that his point isn't valid, but it's the way that he's stated it. The fact is that it's been stated rather than being presented as an argument.
Oh note the good sideswipe about bloatedness at the end. Totally unrelated comment coming into play. Nice.
So, it seems, no matter what you're language (or topic) you're going to run across some FUD.
To be honest, I think it's too early to be making any statements about Perl 6 as a language - it's still in development and we'll only see the results when we have the results. What would be nice is some debate though...I'm always up for some healthy dialog. The trouble with this is that FUD, be it in my favor or against it, isn't healthy dialog - hell, it's not even dialog.
 I'm not saying it will be easier to use Perl 6 day to day. We were arguing that the language changes might have the potential to be so.