The number 1 reason: RSVP
Yes, RSVP is good for helping you track who is coming and not and helping you make seating plans BUT it is a horrible user experience for the guest and, as the bride, I am embarrassed to be sending this to my guests.
The issues with the system are very simple:
The Knot should not require guests email to move forward. They do not even allow the couple to say they want the email from the guest, I know I don't as I already have my friends and family's email address.
Example: If you invite Timmy + 1 and Timmy decides not to bring that guest, an email is still required for that 'guest' in order for Timmy to let you know he is coming and not bringing anyone with him.
The only reason why the know has this as a required field must be for their own purposes. This is a horrible business model....customers should come first.
The next issue is that you can't edit anything on the page of RSVP.
What does this mean for me who already has everything done on the website and the invitations ready to go?
It means I have to add a separate page to my website letting my guests know that they have to include an email, even if their guest is not coming.
I am in the position where I don't have the time to transition my website to another platform leaving me obligated to continue to use the knot which I can say I am embarrassed to because it is a poor experience for my guests.
I emailed support with no answer only to call and be told "we are not the developers" and that others complain about it. It is such a simple fix (I work in Tech) its an on off switch in their system. Oh, I would also have privately provided this feedback but there is no such place to do so.