I have seen both sides of the cutting table as far as uneven cuts. There are some legit reasons. Sometimes the fabric is printed crooked and they may be trying to square it up..never really works.. hate when they cut a panel with out opening it flat...its never lined up and your always missing a piece. Also from being a fabric manager for so many years I have seen way too many customers try and straighten what they think from their angle is crooked after you start to cut...this either gives you a wonky cut or results in wasted time as the cutter must now realign it.

I have gotten a few crooked cuts from online ordering but always check and the goods are always replaced if I fee I can't deal with it...as was the case with a panel I bought was so crooked that the 4 outside corners pieces were wasted only got 4 pictures out of 8 so I called and they sent me a new piece and I also got to keep the old one.

I tend to use a 4 x14 ruler as my main cutting ruler. easier to control and my belly doesn't bump it when i get to the far end knocking it out of wack