Not true for my area! There are quite a few bands here with members working day jobs and the band routinely make $1500+ on a regular basis. One of them is truly mediocre at best and make double that regularly! Weekend warriors can (and do) absolutely work every weekend.
While that is great for them, I would offer that those bands, or your area, is the exception rather than the rule. Sure, we can pick out a few areas where there are some bands who have stuck around long enough to keep good gigs in the pipeline. But years ago, there seemed to be more of a tier system. Everybody knew who the hacks were, who the good weekend warrior bands were, and who the pros were. The pay grade, and overall quality of gigs, reflected which category you were in. Now, it seems to me anyway, that the guys in the middle are forced to make a choice of committing the time to go for semi-pro status, or if you don't have that kind of time commitment, go play dive bars. The middle ground is dwindling in many areas. Just from my own experience of course, anecdotal as it may be.