First I will say that I don't know when this document was released.
The writers say that they don't have experience with the PSL, and honestly, it shows. Their analysis of the PSL comes of as surface level and dismissive, bordering on misinformation. The PSL section is short because it consists of two pieces of information.
The first was a complaint that the party's program didn't say enough about strategy... which isn't the point of a program. The point of a program is to provide people who may be interested a quick description of the party's goals and focus. To sell them on the party. There is (and has been for years) PSL material on strategy on the party site and Liberation School and more recently the party put great effort into the writing of Socialist Reconstruction, a book that is the most detailed and specific plan for the building of socialism in the US that I am aware of.
The rest of the section is cherry picking one PSL initiative? Declaring it PSL's "major project" of 2017 as if it's the only thing PSL did that year? First, when you are looking at planning an event or initiative, it can be externally facing or internally facing. An externally facing event is to immediately connect with the masses who have been depoliticized and draw them close to the org. Internally facing events are to open a space where people already close to an org can engage in political work or development, and may not immediately interest depoliticized workers. Honestly, going to one of an orgs events that clearly is more internally focused - a space for comrades or other interested people to plan other events and develop as organizers - and then bring surprised you see other people already interested in organizing and then concluding the org does no externally facing events, is just disingenuous.
This article reflects a larger problem I see in ML spaces. There is a lip service acknowledgement that "the ground work" must be done but people don't want to be the ones to do it. This article even goes to talk about how great the PSL's "justice center strategy" is and says others should do it... but don't go with the PSL... because. Because they are looking for a party that has already done the work to connect with the masses, not one that is building that relationship.
There is this strange trend that this article is a part of that I have seen other places, notably a growing "anti revisionist" ML YouTube channel. This trend criticizes all existing parties as having made too many mistakes and not adhering to ML principles. Then after all that is done this trend bemoans how small or undeveloped these parties are and abandons all Leninist principles of the importance of a correct line or the need for a vanguard and collective action and tells people to organize with the Green party or with disparate localist groups.
Anyway this has brought out a rant I have had in me for a while. I don't have anything against the authors and don't think they purposely attacked the PSL.